The EU has announced investigations into some of the biggest tech firms in the world over uncompetitive practices.
Alphabet, which owns Google, Meta, and Apple are all being looked into for potential breaches of the Digital Markets Act (DMA) introduced in 2022.
If they are found to have broken the rules, the firms can face huge fines of up to 10% of their annual turnover.
EU antitrust boss Margrethe Vestager and industry head Thierry Breton announced the investigations on Monday.
It comes three weeks after the EU fined Apple €1.8bn (£1.5bn) for breaking competition laws over music streaming.
Meanwhile, the United States accused Apple of monopolising the smartphone market in a landmark lawsuit against the tech giant introduced last week.
In its investigation announced by the EU, it says it believes Apple and Alphabet are limiting anti-steering – in other words, making it difficult for apps to tell users about ways to pay less for their services outside of using app stores’ own payment methods.
It is also looking into whether Meta has breached its rules through asking people to pay to avoid their data being used for adverts.
The move has “forced millions of users across Europe into a binary choice: pay or consent,” said Mr Breton.
According to Ms Vestager, the investigation will take around 12 months to complete.