Meta Platforms Inc & Ors v Dr Liza Lovdahl Gormsen

An appellate court should be slow to interfere with a specialist tribunal’s case-management decision to permit an amendment where the legal issue is novel, fact-sensitive and may develop at trial. A claim for user damages should not be rejected summarily merely because the alleged wrong is not a proprietary tort.

User damages are compensatory. They may measure the economic value of a valuable asset or right which a defendant has wrongfully exploited, where ordinary loss measures may be inadequate. It was strongly arguable that this approach could extend to data obtained through an abuse of dominance under section 18 of the Competition Act 1998.

The respondent was the class representative in opt-out collective proceedings on behalf of Facebook users. She alleged that Meta abused a dominant position by requiring users, on unfair terms, to provide off-platform data without a fair transfer of value.

The Competition Appeal Tribunal permitted an amendment which advanced user damages, assessed through a hypothetical negotiation and Nash bargaining model, as an alternative measure of loss. Meta appealed, contending that user damages were unavailable for a competition-law breach. The appeal was from the Competition Appeal Tribunal’s decision in [2025] CAT 55.

The central issue was whether the amendment should have been refused because the proposed remedy was legally unarguable.

1. Appeal dismissed. Green LJ, with whom Phillips and Zacaroli LJJ agreed, held that the CAT was entitled to allow the amendment. An appellate court should rarely interfere with the CAT’s evaluative case-management judgment. The availability and adequacy of ordinary compensatory damages, and the role of a Nash analysis, depended on evidence that had not yet been obtained or tested. A novel and developing issue should ordinarily be resolved on facts found at trial rather than assumed pleadings.

2. The court’s conclusion on case management was sufficient to dispose of the appeal. It nevertheless held that Meta’s contrary legal case was not established. Stoke-on-Trent City Council v W & J Wass Ltd [1988] 1 WLR 1406 did not impose a closed list of proprietary torts for which user damages could be awarded. Its reasoning recognised that the common law may develop, subject to close examination of the right and statutory scheme concerned.

3. Devenish Nutrition v Sanofi-Aventis did not determine that user damages can never be awarded for a competition-law breach. The Court of Appeal decision concerned the distinct question whether a restitutionary account of profits was available where conventional compensatory damages for a cartel overcharge were adequate. Later authority, especially One Step v Morris-Garner [2018] UKSC 20 and Lloyd v Google [2021] UKSC 50, explained that user damages are compensatory and may value a commercially valuable right or asset wrongfully exploited by a defendant.

4. Section 18 of the Competition Act 1998 is not confined to correcting market distortion through one prescribed counterfactual method. It can encompass exploitative misuse of valuable rights and protect consumers. It was therefore strongly arguable that, if necessary to redress an abuse effectively, the CAT could award user damages. Consent obtained through unfair and exploitative terms could also arguably be void or declared ineffective.

• Court of Appeal (Civil Division) — dismissed Meta’s appeal and upheld the permission to amend.
• Competition Appeal Tribunal — in [2025] CAT 55, permitted the class representative to amend her pleading to advance user damages and related allegations.