Several social media and streaming services are engaging in “vast surveillance” of their users, including children, by collecting and sharing personal information, the Federal Trade Commission has disclosed.

The findings, released Thursday, stem from a comprehensive study of nine major companies, including Meta, YouTube, and TikTok. According to the report, the platforms — which primarily offer free services — capitalize on consumer data by using it for targeted advertising based on user demographics.

The investigation also highlighted the companies’ failure to adequately protect users, particularly children and teenagers.

The FTC initiated the study nearly four years ago to provide the first in-depth analysis of the opaque business practices of some of the largest online platforms, which have built multibillion-dollar advertising businesses using consumer data. The agency’s report underscores the necessity for federal privacy legislation and tighter controls on data collection and usage.

“Surveillance practices can endanger people’s privacy, threaten their freedoms, and expose them to a host of harms, from identity theft to stalking,” the chairman of the the FTC, Lina Khan, said in a statement.

Despite several legislative proposals aiming to enforce stricter privacy and online safety protections for children, almost all attempts at regulating Big Tech have stalled in Congress. The FTC’s report also concluded that efforts by these companies to regulate themselves have been ineffective. “Self-regulation has been a failure,” the agency said.