EU tech regulators charged social media platform TikTok on Friday with breaching the bloc's online content rules due to the so-called "rabbit hole" effect of its recommender system, which attracts users' attention to a constant stream of similar videos.
TikTok's Chinese owner ByteDance risks a fine next year of up to 6% of its global annual turnover unless it can resolve the issue.
Social media companies are under pressure to modify their algorithms amid growing concerns worldwide that their platforms are contributing to a mental health crisis among children, prompting some governments to impose or consider bans for underage users.
The European Commission, which acts as the EU tech regulator, said it issued charges known as preliminary findings to TikTok after the company failed to implement proportionate, reasonable and effective mitigation measures to address the risks.
It said endless and repeated exposure to content about sadness, isolation or body image can have a detrimental impact on users' mental health.
"Every time a user scrolls or likes a video on TikTok, the algorithm serves more of the same leading users down rabbit holes they cannot easily escape from," EU tech chief Henna Virkkunen said in a statement.
"Today's preliminary findings show again that TikTok needs to step up its efforts to protect users' well-being, including those of minors," she said.
The Commission said TikTok needs to change the design of its 'For You' feed algorithm and should rely more on users' explicit preferences, increase the accessibility and usability of user controls and regularly test its algorithm, among other changes.
The charges are under the EU's Digital Services Act which requires big online platforms to do more to tackle harmful and illegal content on their platforms.
The latest charges are part of a broader EU investigation into TikTok.
EU regulators charged TikTok in February over what regulators said were the platform's addictive designs, inadequate efforts to protect children and making it difficult for researchers to request access public data.
TikTok said at the time that those preliminary findings were "categorically false" and it would take steps to challenge them.
The Commission is ?separately investigating so-called rabbit hole effects caused by Meta Platforms' Facebook and Instagram recommendation systems.
