Civil Law and Data Monopolies: Civil Liability for Abuse of Market Power in Europe

1. Introduction

“Data monopolies” refers to situations where an undertaking obtains or controls a very large amount of commercially valuable data and uses that position to strengthen or exploit its market power.

Examples include:

search-engine data;

social-network data;

advertising data;

consumer purchasing data;

location data;

financial and transaction data;

business-to-business datasets;

platform-generated data;

behavioural profiles;

data obtained from connected devices.

European law does not treat possession of large quantities of data as automatically unlawful. The legal problem arises where a dominant undertaking uses its data advantage in a way that constitutes an abuse of dominance, restricts competition, harms customers or competitors, or violates related legal duties.

Article 102 TFEU prohibits abusive exploitation of a dominant position. Importantly, dominance itself is not prohibited; the prohibited conduct is its abusive exploitation. Recent CJEU case law confirms that exclusionary conduct must generally be assessed by examining whether methods other than competition on the merits are capable of restricting competition. (Curia)

Civil liability is the private-law side of this framework. A business or consumer harmed by abusive conduct may potentially seek:

damages;

restitution;

recovery of overcharges;

compensation for lost profits;

injunctions;

contractual remedies;

cessation of unlawful conduct;

disclosure of evidence;

other remedies under applicable national law.

The EU Damages Directive expressly recognises compensation for harm caused by infringements of Articles 101 and 102 TFEU and requires Member States to provide effective procedures for such claims. (EUR-Lex)

2. Meaning of a Data Monopoly

A data monopoly may arise where one undertaking possesses a particularly important and difficult-to-replicate dataset.

For example:

A digital platform has millions of users, collects their search, purchasing and behavioural information, and uses that information to improve its own services while preventing competitors from accessing comparable data.

The legal issue is not simply:

“Who has the most data?”

Instead, courts may ask:

Does the undertaking have a dominant position?

Is the data commercially important?

Is the data difficult for competitors to reproduce?

Is access to the data necessary or particularly important for effective competition?

Has the dominant undertaking restricted access?

Has it combined data from different services?

Has it discriminated against competitors?

Has it used data obtained from business partners to compete against them?

Has it self-preferenced its own services?

Has the conduct caused identifiable harm?

3. Difference Between Data Monopoly and Ordinary Monopoly

4. Main European Legal Framework

The principal framework consists of:

A. Article 102 TFEU

It prohibits abusive exploitation of a dominant position affecting trade between Member States.

B. National competition law

Member States frequently have domestic provisions corresponding to Article 102 TFEU.

C. EU Damages Directive 2014/104/EU

It establishes rules facilitating private damages actions for competition-law infringements.

The Directive provides for full compensation covering actual loss, loss of profit and interest, while preventing overcompensation. (EUR-Lex)

D. GDPR

Where the data monopoly concerns personal data, the GDPR may become relevant.

E. Consumer law

Consumers may have additional rights concerning unfair contractual practices, transparency and unlawful exploitation.

F. Digital Markets Act

For designated gatekeepers, the DMA imposes additional obligations concerning data combination, interoperability, access and competitive conduct.

5. Case Law 1 — Meta Platforms and Others v Bundeskartellamt, C-252/21

Court: CJEU
Date: 4 July 2023

This is one of the most important European cases concerning data accumulation and market power.

Meta operated Facebook and collected data not only from Facebook but also from other Meta services and third-party websites and applications.

The German Federal Cartel Office considered that Meta's processing of “off-Facebook” data could be relevant to its abuse-of-dominance assessment.

The CJEU held that a national competition authority may, in the context of an abuse-of-dominance investigation, examine whether data processing complies with the GDPR, while respecting the competence of data-protection authorities and the principle of sincere cooperation. (curia)

Importance for civil liability

This case demonstrates that:

Data protection and competition law can interact when a dominant platform uses data as part of its market power.

A claimant could therefore potentially rely on evidence concerning:

excessive data collection;

cross-service data combination;

lack of meaningful consent;

exploitation of a dominant position;

foreclosure of competing services.

However, a GDPR infringement and a competition-law infringement are not automatically the same thing. The applicable legal elements must separately be established.

6. Case Law 2 — Google and Alphabet v Commission (Google Shopping), C-48/22 P

Court: CJEU
Date: 10 September 2024

Google Shopping concerned Google's dominant position in general search services and its treatment of competing comparison-shopping services.

Google gave prominent placement to its own comparison-shopping service while competing services were demoted in search results.

The CJEU dismissed Google's appeal and upheld the finding of abuse. The Court examined the conduct as a form of leveraging involving Google's dominant general-search service and its specialised comparison-shopping service. (curia)

Relevance to data monopolies

Although this was not technically a “data monopoly” case, it is highly relevant to data-driven markets.

A platform may control:

user attention;

search information;

behavioural information;

ranking algorithms;

traffic;

advertising information.

It may then use that position to favour its own downstream service.

Civil-law significance

Competitors claiming damages may need to demonstrate:

dominance → abusive conduct → anticompetitive effect → causation → quantifiable harm.

The Google Shopping litigation therefore illustrates how digital market power can produce potentially compensable private harm.

7. Case Law 3 — Servizio Elettrico Nazionale and Others, C-377/20

Court: CJEU
Date: 12 May 2022

This case concerned the Italian electricity market rather than a digital platform.

However, it is important for understanding the legal test for abuse of dominance.

The case involved the transfer of commercially sensitive information within a corporate group in circumstances connected with preserving a dominant position inherited from a legal monopoly.

The CJEU explained that exclusionary abuse requires examination of whether conduct using methods other than competition on the merits is capable of producing exclusionary effects. (curia)

Relevance to data monopolies

The principle can apply by analogy to data:

A dominant undertaking cannot necessarily use commercially sensitive information obtained through its market position to protect or extend that position through means falling outside competition on the merits.

For a civil claim, the claimant would still have to establish actual legally compensable harm.

8. Case Law 4 — Deutsche Telekom v Commission, C-280/08 P

Court: CJEU
Date: 14 October 2010

Deutsche Telekom involved a dominant telecommunications undertaking and a margin-squeeze theory.

The CJEU upheld the finding of abuse.

The case demonstrates that a dominant undertaking can abuse its position through the structure of its pricing arrangements even where competition occurs in related markets. (curia)

Data-market analogy

In data markets, a similar analytical problem can arise where a dominant platform:

controls an important input;

provides access to that input on discriminatory terms;

competes downstream with companies requiring that input;

structures commercial terms so competitors cannot effectively compete.

The “input” in a modern digital market could potentially be:

data;

advertising inventory;

platform access;

technical information;

APIs;

interoperability;

user-generated information.

9. Case Law 5 — Courage v Crehan, C-453/99

Court: CJEU
Date: 20 September 2001

Courage established an important foundation for private competition-law enforcement.

The case concerned an anti-competitive contractual arrangement and whether a party could seek damages.

The Court recognised that EU competition law requires effective remedies for persons harmed by competition-law infringements, while also considering the claimant's own role in the unlawful arrangement. (InfoCuria)

Importance for data monopolies

The case establishes a broader principle:

Competition law is not merely a matter for regulators; individuals and businesses can have rights arising from competition-law infringements.

Therefore, a company harmed by a dominant digital platform may potentially pursue a civil claim rather than relying exclusively on regulatory enforcement.

10. Case Law 6 — Vantaan kaupunki v Skanska, C-724/17

Court: CJEU
Date: 14 March 2019

Skanska concerned liability following an anti-competitive cartel and corporate restructuring.

The Court applied the concept of the economic entity/undertaking and the principle of economic continuity in determining who could be liable for competition-law damages. (InfoCuria)

Importance for data monopolies

This becomes significant where a dominant digital business:

transfers a data business;

restructures its subsidiaries;

sells a platform;

transfers assets;

merges with another undertaking;

changes corporate identity.

A corporate restructuring cannot necessarily be used simply to defeat competition-law liability.

11. Case Law 7 — Sumal v Mercedes-Benz Trucks España, C-882/19

Court: CJEU
Date: 6 October 2021

Sumal concerned whether a subsidiary could be sued for damages resulting from anti-competitive conduct attributed to its parent company.

The CJEU recognised circumstances in which a victim can bring a damages action against a subsidiary within the same economic unit, subject to the requirements established by the judgment. (InfoCuria)

Importance for digital groups

This principle can become important for large technology groups having:

European subsidiaries;

national operating companies;

advertising subsidiaries;

cloud businesses;

data-processing entities;

platform subsidiaries.

A claimant may investigate the economic unit rather than looking only at the formal corporate entity that directly performed the conduct.

However, Sumal does not mean that every subsidiary is automatically liable. The required economic and functional connection must be established.

12. Case Law 8 — Skanska and Sumal: Economic-Unit Liability

Together, Skanska and Sumal establish an important civil-liability principle.

Competition-law liability may follow the economic reality of an undertaking rather than merely its formal corporate structure.

This is particularly important for data monopolies because digital businesses often operate through complex structures:

Parent company → European subsidiary → national subsidiary → platform → advertising entity → data-processing entity.

The claimant must therefore examine:

ownership;

control;

economic unity;

business activities;

relationship with the infringement;

role of the relevant subsidiary.

13. What Constitutes Abuse of a Data-Based Dominant Position?

Several forms of conduct may potentially constitute abuse.

A. Refusal to provide access to important data

A dominant platform may possess data that competitors cannot reasonably reproduce.

A refusal can become legally significant where the applicable strict requirements for abusive refusal/access conduct are satisfied.

B. Discriminatory data access

Example:

Platform gives its own affiliated business full access to commercially important information but provides competitors with inferior access without objective justification.

Possible legal issues include:

discrimination;

foreclosure;

self-preferencing;

leveraging;

exclusionary abuse.

C. Self-preferencing

A platform can use its data and technological position to favour its own services.

Google Shopping illustrates the broader European concern with preferential treatment by a dominant digital platform. (curia)

D. Data combination

A dominant platform may combine:

social-media information;

browsing information;

advertising data;

purchasing data;

location information;

third-party information.

Meta is particularly important because the CJEU examined the combination of Facebook information with “off-Facebook” information in the competition-law context. (InfoCuria)

14. Data Hoarding

Data hoarding means accumulating large quantities of data in circumstances that potentially prevent effective competition.

Examples:

collecting more data than reasonably necessary;

preventing competitors from accessing important datasets;

refusing interoperability;

imposing restrictive API conditions;

acquiring competitors primarily to consolidate datasets;

combining datasets from different markets;

using historical data unavailable to new entrants.

But large-scale data accumulation alone does not prove an abuse.

The claimant must establish the relevant competition-law elements.

15. Network Effects

Data monopolies are frequently strengthened by network effects.

For example:

More users → more data → better service → more users → more data.

This can create a feedback loop.

Legal significance

A competitor may face difficulty entering the market because it does not possess the incumbent's historical data.

Therefore, market power may arise from the combination of:

data;

users;

algorithms;

infrastructure;

network effects;

brand;

switching costs.

16. Data as an Essential Input

One of the most difficult questions is whether particular data should be regarded as an indispensable or exceptionally important input.

The analysis can consider:

Is the data technically obtainable elsewhere?

Can competitors collect equivalent data?

How expensive is replication?

Is the dataset unique?

Is it updated continuously?

Does it contain historical information?

Does the undertaking have exclusive access?

Is access legally restricted?

Would access materially improve competition?

The mere fact that data is valuable does not automatically make it an “essential facility.”

17. Civil Liability: The Basic Structure

A simplified civil claim can be expressed as:

Dominant position

↓

Abusive conduct

↓

Competition-law infringement

↓

Economic or other legally recognised harm

↓

Causal connection

↓

Compensation

This distinction is extremely important.

A claimant cannot normally say:

“The company is dominant, therefore it owes me damages.”

Instead:

Dominance + abuse + infringement + causation + damage

must be established according to the applicable legal framework.

18. Types of Damage

1. Overpayment

A business or consumer may have paid more because of abusive conduct.

2. Lost profits

A competing business may claim profits it would allegedly have earned without the exclusionary conduct.

3. Loss of market share

A competitor may argue that exclusion caused measurable commercial loss.

4. Loss of business opportunity

Depending on applicable national law and proof, loss of opportunity may become relevant.

5. Investment losses

A competitor may have invested in:

technology;

employees;

marketing;

infrastructure;

but failed to recover those investments because of exclusionary conduct.

6. Data-related economic loss

A company could potentially claim losses associated with:

restricted access to commercially important data;

discriminatory data access;

loss of customers;

reduced advertising opportunities;

inability to compete effectively.

19. Full Compensation Principle

The EU Damages Directive requires Member States to ensure that persons suffering harm from competition-law infringements can obtain full compensation.

Full compensation covers:

actual loss;

loss of profit;

interest.

It should restore the claimant to the position it would have occupied absent the infringement and should not create overcompensation. (EUR-Lex)

20. Passing-On Problem

Suppose a business claims:

“The data monopoly caused me €10 million in overcharges.”

The defendant may argue:

“You passed those costs to your customers.”

This creates the passing-on problem.

The Damages Directive expressly deals with passing-on and aims to ensure that compensation goes to the party that actually suffered the harm while avoiding double recovery. (EUR-Lex)

21. Causation

Causation is often the most difficult part of a data-monopoly damages action.

The claimant may have to establish:

Abusive data practice → reduced competition → specific commercial harm.

For example:

Dominant platform restricted access to consumer data → competitor's targeting efficiency fell → customer acquisition costs increased → sales declined.

The court must determine whether the alleged losses were actually caused by the infringement rather than by:

poor management;

economic recession;

technological change;

consumer preferences;

unrelated competitors;

product quality;

ordinary business risk.

22. Counterfactual Analysis

Courts and economic experts may ask:

What would have happened if the abuse had not occurred?

This is called a counterfactual.

Possible comparisons include:

prices before and after the conduct;

markets where the conduct did not occur;

comparable geographical markets;

comparable products;

hypothetical competitive pricing;

expected data access;

market-share development.

This can require complex economic evidence.

23. Evidence in Data-Monopoly Litigation

Important evidence may include:

Technical evidence

APIs;

server logs;

algorithms;

data architecture;

access permissions;

databases;

interoperability documentation.

Commercial evidence

contracts;

pricing documents;

platform terms;

internal business plans;

emails;

strategic documents.

Competition evidence

market-share data;

entry barriers;

switching rates;

customer surveys;

competitor access conditions.

Data evidence

dataset size;

uniqueness;

data quality;

data acquisition methods;

historical datasets;

data-combination practices.

24. Relationship Between GDPR and Competition Law

The Meta C-252/21 judgment is particularly important.

The CJEU accepted that a competition authority can consider GDPR compliance when examining abuse of dominance, while requiring coordination with the competent data-protection authorities. (curia)

Thus:

The two regimes can therefore operate together, but they remain legally distinct.

25. Data Monopolies and Consumer Harm

Consumers may be harmed through:

higher prices;

reduced quality;

reduced choice;

reduced innovation;

excessive data extraction;

reduced privacy;

discriminatory algorithms;

restrictive platform conditions.

Digital services may appear “free” because users do not pay money directly.

But competition analysis can still consider non-price dimensions such as:

privacy;

quality;

innovation;

data collection;

service conditions.

Meta illustrates how personal-data processing can become relevant to competition analysis in a dominant digital platform. (curia)

26. Data Monopolies and Competitor Harm

Competitors may suffer:

Direct harm

The dominant company prevents access to important data.

Indirect harm

The dominant company uses data to improve its own competing product.

Foreclosure

The competitor cannot achieve sufficient scale.

Innovation harm

The competitor cannot develop competing services because it lacks equivalent data.

27. Data Advantage vs Abuse

This distinction is essential.

Lawful situation

A company creates a successful dataset through legitimate innovation.

Potentially problematic situation

A dominant undertaking:

unlawfully obtains competitors' data;

discriminates in data access;

combines data in a way that creates exclusionary effects;

uses privileged information to foreclose competitors;

restricts interoperability;

exploits contractual or infrastructural control.

Therefore:

Data advantage ≠ automatically unlawful monopoly.

28. Corporate Group Liability

Large technology businesses commonly have numerous subsidiaries.

The cases Skanska and Sumal are important because EU competition law can examine the economic unit rather than simply the formal corporate structure. (InfoCuria)

For civil litigation, lawyers therefore examine:

parent company;

subsidiaries;

data controller;

platform operator;

advertising company;

cloud company;

European operating entity.

However, liability cannot simply be imposed on every company within a corporate group.

29. Role of the EU Damages Directive

The Directive is extremely important for civil liability.

Its framework includes:

right to full compensation;

actual loss;

loss of profit;

interest;

evidence disclosure;

limitation periods;

binding effect of infringement decisions in relevant circumstances;

passing-on;

joint and several liability;

protection of certain leniency arrangements.

The Directive states that individuals and businesses may claim compensation even without a direct contractual relationship with the infringer. (EUR-Lex)

30. Public Enforcement and Private Enforcement

There are two major mechanisms.

Public enforcement

Competition authority:

Investigation → infringement decision → fine/remedy

Private enforcement

Victim:

Infringement → civil action → proof of damage → compensation

The EU framework expressly recognises the complementary relationship between public and private enforcement. (EUR-Lex)

31. Important Case-Law Table

The first two are particularly important for modern digital/data markets; the others supply broader principles for abuse and private enforcement. (InfoCuria)

32. Defences Available to a Data-Dominant Company

A defendant may argue:

It is not dominant.

The relevant market has been defined incorrectly.

Data is readily available elsewhere.

Competitors can reproduce the dataset.

Conduct constitutes competition on the merits.

There is an objective justification.

There is no exclusionary effect.

There is no causal connection.

The claimant suffered no legally compensable damage.

The claimant's losses resulted from independent factors.

The claimant passed the alleged overcharge to customers.

The claim is time-barred.

The wrong defendant has been sued.

33. Claimant's Arguments

A claimant may argue:

the defendant possesses durable market power;

the data is difficult to replicate;

competitors depend upon the dataset;

access was restricted;

the dominant company used the data against competitors;

data was combined across markets;

self-preferencing occurred;

contractual restrictions reinforced market power;

the conduct foreclosed equally efficient competitors;

the conduct caused measurable economic harm.

34. Civil Remedies

Depending on the jurisdiction and claim, possible remedies include:

Damages

Compensation for actual loss and lost profits.

Restitution

Recovery of improperly obtained economic benefits where national law permits.

Injunction

Order requiring the undertaking to stop unlawful conduct.

Access remedy

In appropriate circumstances, an order concerning access to data or infrastructure.

Contractual remedy

Invalidity, modification or damages concerning unlawful contractual arrangements.

Declaratory relief

Court declaration concerning rights and obligations.

35. Special Problem: “Free” Digital Services

Traditional competition law often focuses heavily on price.

Data markets can be different.

A consumer may pay:

€0

but provide:

personal data;

behavioural information;

attention;

location information;

purchasing information.

Consequently, competition can occur through privacy, quality and data conditions, rather than only monetary prices.

This makes data monopolies particularly complicated from a civil-liability perspective.

36. Data Monopolies and Innovation

A dominant data platform can potentially affect innovation by:

restricting competitors' access to datasets;

acquiring innovative startups;

using competitor data to improve its own products;

imposing restrictive interoperability terms;

controlling APIs;

preventing multi-homing.

A claimant must nevertheless demonstrate the legally relevant competitive harm rather than merely asserting that innovation was reduced.

37. Data Monopolies and Mergers

Data accumulation can also become relevant during mergers.

A transaction may combine:

Dataset A + Dataset B = substantially stronger information advantage.

Competition authorities may examine:

market concentration;

data uniqueness;

entry barriers;

network effects;

ability to replicate data;

potential competition;

innovation.

This is generally an ex ante competition issue, whereas civil damages litigation is usually ex post and focuses on an infringement and resulting harm.

38. Cross-Border Civil Litigation

Data businesses frequently operate across Europe.

A claimant may therefore encounter questions concerning:

jurisdiction;

applicable law;

location of damage;

defendant's domicile;

cross-border evidence;

limitation periods;

enforcement of judgments.

The EU competition framework seeks to ensure that procedural rules do not make the right to compensation practically impossible or excessively difficult. (EUR-Lex)

39. Role of Economic Experts

Data-monopoly cases often require economists to calculate:

hypothetical competitive prices;

market shares;

foreclosure effects;

lost sales;

lost profits;

counterfactual market development;

customer acquisition costs;

value of data access;

overcharges.

Technical experts may separately analyse:

data architecture;

algorithmic systems;

interoperability;

API restrictions;

dataset uniqueness.

40. Practical Example

Suppose Company A operates Europe's largest online marketplace.

It possesses:

millions of customer transactions;

seller information;

purchasing histories;

product searches;

advertising information.

It then launches its own competing product.

Company A:

collects seller data;

identifies successful products;

uses that information for its own products;

gives its own products preferential visibility;

restricts competitors' access to important data.

A competitor loses €20 million in expected profits.

The competitor may potentially claim:

dominance → abusive conduct → foreclosure → causation → €20 million loss.

But the court would still need evidence establishing each relevant element.

41. Key Legal Distinctions

Dominance vs abuse

Dominance alone is not unlawful.

Data ownership vs market power

Owning data does not automatically create dominance.

Privacy violation vs competition infringement

A GDPR violation does not automatically establish Article 102 liability.

Competition infringement vs damages

An infringement does not automatically establish the amount of civil damages.

Parent company vs subsidiary

Corporate affiliation does not automatically establish liability.

Data value vs essential facility

Valuable data is not automatically an indispensable facility.

42. Overall European Approach

European law is moving toward a more integrated understanding of digital market power.

The important development is the interaction between:

Competition law + civil liability + data protection + digital regulation.

The Meta judgment is particularly significant because it demonstrates that data-processing practices can become relevant to the assessment of dominance and abuse. (curia)

The Google Shopping judgment demonstrates that digital-platform conduct can constitute an abuse where a dominant undertaking uses its position to favour its own related service and harm competitive conditions. (curia)

The private-enforcement cases such as Courage, Skanska and Sumal demonstrate how competition-law principles can translate into civil liability and damages claims. (curia)

43. Conclusion

Data monopolies are not unlawful merely because one company controls a very large dataset. The legal problem arises where data-based market power is combined with conduct amounting to abuse of dominance or another actionable infringement.

European civil liability generally requires a chain such as:

Dominant position → abusive conduct → competition-law infringement → causation → identifiable harm → compensation.

The most important cases for understanding the subject are Meta Platforms (C-252/21), Google Shopping (C-48/22 P), Servizio Elettrico Nazionale (C-377/20), Deutsche Telekom (C-280/08 P), Courage v Crehan (C-453/99), Skanska (C-724/17), and Sumal (C-882/19).

The modern European approach therefore treats data not simply as an information asset, but potentially as a source of economic power, competitive advantage and civil liability when its control is connected with abusive market conduct.

44. Ultra-Basic Keywords for Revision

Data Monopoly – control over important data
Dominance – substantial market power
Article 102 TFEU – prohibition of abuse of dominance
Abuse – improper exploitation of dominance
Data Access – availability of important datasets
Data Hoarding – accumulation/control of data
Self-Preferencing – favouring own service
Leveraging – using power in one market to affect another
Foreclosure – excluding competitors
Network Effect – more users → more data → stronger service
Essential Input – particularly important input
Data Combination – joining datasets
GDPR – EU data-protection framework
Civil Liability – private legal responsibility
Damages – monetary compensation
Causation – connection between abuse and harm
Lost Profit – profit claimant would have earned
Overcharge – excessive price caused by infringement
Passing-On – transferring increased costs to customers
Counterfactual – what would have happened without abuse
Economic Unit – group treated as one undertaking for relevant competition-law purposes
Courage – private enforcement
Skanska – economic continuity
Sumal – subsidiary liability
Meta – data + dominance + GDPR
Google Shopping – digital self-preferencing/leveraging
Servizio Elettrico – exclusionary abuse
Deutsche Telekom – margin squeeze
Full Compensation – actual loss + lost profit + interest.