A new EU law comes into effect Wednesday that imposes stricter online regulations, and major platforms like Facebook and Google will have until February 17 to reveal their user numbers. The Digital Services Act (DSA) rules will go into full effect in 12 months from February 17, 2024, but officials will need time next year to decide which tech giants are big enough to need close scrutiny.

DSA was designed to combat online hate speech, disinformation and piracy in Europe at a time when most of the internet content viewed by EU citizens is controlled by US-based companies. Under the new law, all social media platforms, online marketplaces and search engines will have to respond faster to remove content deemed to be against EU rules. This will include measures to limit the use of sensitive personal data in targeting ads to European users, and will insist on greater transparency for algorithms that recommend content.

But the new rules will come into effect sooner for what Brussels calls very large online platforms (VLOPs) and very large online search engines (VLOSEs) with more than 45 million active users in the EU. In current user numbers, the definition will hit around 20 companies, including Meta and its social networks Facebook and Instagram; Google and YouTube video platform; and iPhone maker Apple’s platforms.

Microblogging platform Twitter, recently acquired by entrepreneur Elon Musk, will almost certainly be included, along with Chinese video sharing platform TikTok, German retailer Zalando, and Dutch hotel site Booking. Any site that may be large enough to qualify for the deduction must publish European user numbers by 17 February 2023, and the DSA rules will go into effect when the European Commission approves their size.

For devs, this means that stricter DSA rules for major platforms could arrive in late 2023 instead of February 2024, when they will apply to everyone. VLOPs can be fined up to six percent of their global revenue or even banned from the major EU market for serious and persistent violations. The DSA complements another new EU law, the Digital Markets Act, or DMA, which came into force in November and bans anti-competitive behavior by so-called internet “watchdogs”.