TikTok is breaching millions of European users’ rights “on a massive scale,” and authorities should take “swift action” to protect consumers—particularly children, according to leading European consumer organization BEUC.

BEUC has filed a complaint with the European Commission, while consumer rights’ organizations in 15 EU countries have urged their national authorities to also investigate the social media giant’s conduct and review its policies and practices.

BEUC has also sent a letter to the European Data Protection Board—the EU’s supervisory body that oversees the General Data Protection Regulation (GDPR)—over concerns users’ privacy is not being adequately protected and TikTok’s policies are in “constant flux.”

Based on its research, BEUC believes TikTok—a video sharing platform popular with children and teenagers and owned by Chinese company Bytedance—“falls foul of multiple breaches” of EU consumer rights. Chief among BEUC’s criticisms are that TikTok fails to protect children and teenagers from potentially harmful content and hidden advertising on its platform—areas that are already under heavy EU scrutiny and slated for reform—while its practices for the processing of users’ personal data (and their purpose) are also misleading and unlikely to be comprehensible to children (the minimum legal age for a user is 13 years of age).

“We consider that some of these, as well as other practices, are in breach of the GDPR and have brought them to the attention of data protection authorities in the context of their ongoing investigations into the company,” said BEUC in a statement.

Furthermore, says the consumer group, TikTok’s “terms of service” are unfair, particularly around copyright “grabbing” of users’ content without remuneration, while the platform may also be improperly profiting from financial transactions by manipulating exchange rates in its favor when users buy coins to purchase “virtual gifts” for TikTok “celebrities” whose performance they like (one of the platform’s popular features).

Monique Goyens, BEUC’s director general, stated: “TikTok is letting its users down by breaching their rights on a massive scale.”

“Children love TikTok but the company fails to keep them protected,” she added. “Authorities … must act now to make sure TikTok is a place where consumers, especially children, can enjoy themselves without being deprived of their rights.”

TikTok has faced increasing criticism regarding its privacy and child safety policies following a string of incidents and is already on the radar of several EU data protection authorities over its level of compliance with the bloc’s strict privacy rules.

The company has said it has contacted BEUC to arrange a meeting to listen to its concerns.

In a statement, a TikTok spokesperson said: “Keeping our community safe, especially our younger users, and complying with the laws where we operate are responsibilities we take incredibly seriously.”

The company added it has already taken steps to improve users’ data protection, including making all accounts belonging to users under 16 private by default and developing an in-app summary of its privacy policy with vocabulary and a tone of voice that makes it easier for teens to understand the platform’s approach to privacy.