BRUSSELS — The European Commission on Monday laid out its formal case against Meta over allegedly addictive design features on Facebook and Instagram, setting a deadline for the company to respond to preliminary findings under the Digital Services Act.

The Commission alleges that infinite scroll, autoplay and engagement-driven notifications amount to design choices that harm the mental health of users, particularly minors, in breach of the DSA's requirements to mitigate systemic risks. Meta must submit written observations and may request access to the case file.

Under the DSA, very large online platforms face fines of up to 6 percent of global annual turnover for confirmed breaches. For Meta, whose 2025 revenue exceeded 160 billion dollars, that threshold could translate into penalties running into billions of euros. Repeated infringements can trigger periodic penalty payments.

Henna Virkkunen, the Commission's executive vice-president for technology sovereignty, said the bloc intends to hold platforms accountable for design that exploits users. Meta has previously rejected the accusations, arguing it has introduced teen accounts, default privacy settings and screen-time tools that address regulatory concerns.

The case is part of a widening European effort to regulate engagement-maximizing design, with parallel scrutiny of TikTok and other platforms. A final decision on liability and any fine is not expected for several months, after Meta's response and further Commission review.