Unjust enrichment is a plausible cause of action for individuals whose data has been collected and used without their consent, to train, develop, or improve AI systems, or which has been sold for such purposes. Disgorgement of profits may be possible in some situations where the defendant has unlawfully collected or used personal data. Gain-based remedies have a number of advantages in this context, including the fact that it may be relatively easy to ascertain the gain, but demonstrating the loss will be considerably harder. However, contractual pre-emption may limit the utility of claims for unjust enrichment.