LinkedIn Corp. andMeta Platforms Inc. are among the companies that have been emboldened to train their artificial intelligence on the personal data of European users, testing EU regulators’ approach to privacy enforcement.

After EU data protection authorities in 2024 stopped US tech platforms from training over privacy concerns, the tide turned this year with companies turning back to EU data. Their approach doesn’t require user consent, rather they’re relying on what’s known as the legitimate interest provision in EU privacy law and giving users the ability to opt out.

While there has been no officially policy pronouncement, …