By Sergio Goncalves
LISBON, Sept 10 (Reuters) - Portuguese digital rights group D3 has filed lawsuits against Facebook, Instagram, TikTok and YouTube, accusing them of designing features in their platforms that keep users hooked, it said on Thursday.
The four collective actions, which allow associations to bring cases on behalf of a broader group of consumers, follow on from lawsuits in other countries that have challenged social media's addictive design.
None of the companies that own the platforms
being sued — Meta, ByteDance and Alphabet — immediately replied to Reuters' requests for comment.
Filed by law firm Andersen Tax & Legal Iberia with Lisbon's Civil Court between April and May and disclosed only now after the judicial summer break, the legal action seeks to "hold these platforms accountable and force them to provide a safe experience for their users," D3 said.
D3 highlighted features including infinite scrolling, autoplay videos, persistent notifications and highly personalised recommendation systems found on Meta's Facebook and Instagram, ByteDance's TikTok and Alphabet's YouTube.
By removing natural breaks in usage, constantly serving personalised content and repeatedly prompting users to return, platforms create behavioural feedback loops akin to techniques long used in the gambling industry, D3 said.
"Platforms do not have to be hyper-addictive," D3 President Ricardo Lafuente said.
"A healthy, productive and educational social media ecosystem is possible, but only if the rules are robust, properly enforced and directed at those who persist in ignoring them," he said.
On both sides of the Atlantic, social media has come under mounting scrutiny.
In February, TikTok was charged under EU rules over allegedly addictive features, while in August Meta agreed to pay up to $18 billion to settle U.S. addiction claims.
According to data aggregated by website SocialMediaTransparency.org, the four platforms had a combined reach of 33 million monthly users in Portugal in the first half of 2026.
(Reporting by Sergio Goncalves; editing by Charlie Devereux and Barbara Lewis)
