This has nothing to do with the DMA if that's what you mean.

EU is alleging Meta is infringing on the 1994 EEA Agreement specifically the generic "don't impose unfair trading conditions" clause. Which if it successful should frighten most companies. Because making life harder for your competitors is the entire point of business.

If you leverage your business, and data obtained for other reasons, to unfairly depress competition, the end user loses out, and is part of why antitrust legislation exists.

Another example is what Amazon were accused of - using their internal data from providing seller services to then decide which products to launch in their Amazon Basics range - to the point where it makes those other products no longer profitable to sell, and an option for consumers is removed.

If they conducted research without using that data about what products people would like, that's different - that's competing vigorously and fairly.

This is the most salient point on the thread. People are studiously refusing to frame the discussion around this as pro-consumer, and prefer to maintain that it's nothing more than a proxy success-tax on BigTech.

If you want to operate as a marketplace, the EU denotes certain practices and standards for doing so. Don't like them? Don't operate as such.