Mark Zuckberg’s Meta is to go ahead with controversial plans to use millions of UK Facebook and Instagram posts to train its artificial intelligence (AI) technology, in a practice that is effectively outlawed under EU privacy laws.

Meta said it had “engaged positively” with the Information Commissioner’s Office (ICO) over the plan, after it paused similar proposals in June in the UK and EU. The pause came after the ICO warned tech firms to respect the privacy of users when building generative AI.

On Friday, the ICO made it clear it has not provided regulatory approval for the plan, but will instead monitor the experiment after Meta agreed changes to its approach. These include making it easier for users to opt out of allowing their posts to be processed for AI.

Privacy campaigners, including the Open Rights Group (ORG) and None of Your Business (NOYB), are alarmed at the plans. When the plans were first mooted ORG accused Meta of “turning all of us into involuntary (and unpaid) test subjects for their experiments”. Alongside NOYB it urged the ICO and the EU to block them.

The plans remain on hold in Europe. Meta has accused the EU of holding back the development of AI by refusing to allow EU citizens’ posts to be used for AI training.

But on Friday, Meta confirmed that for UK users of Facebook and Instagram it will resume plans to use publicly shared posts to train AI models. It will not use private messages or any content from those under 18, Meta said.

In a statement, Meta said: “This means that our generative AI models will reflect British culture, history and idiom, and that UK companies and institutions will be able to utilise the latest technology. We’re building AI at Meta to reflect the diverse communities around the world and we look forward to launching it in more countries and languages later this year.”

Stephen Almond, the ICO’s executive director for regulatory risk, said: “We have been clear that any organisation using its users’ information to train generative AI models should be transparent about how people’s data is being used.

“Organisations should put effective safeguards in place before they start using personal data for model training, including providing a clear and simple route for users to object to the processing.”

He added: “The ICO has not provided regulatory approval for the processing and it is for Meta to ensure and demonstrate ongoing compliance.”