On Tuesday, European Union officials led by Ms. Vestager will introduce some of the world’s most far-reaching technology regulations. The rules take aim at so-called gatekeeper platforms, like Amazon, Apple, Facebook and Google, which have an outsize role in the digital economy.Among the expected changes are rules for Facebook, Twitter and YouTube, which is owned by Google, about moderating user-generated content. Other requirements would make companies disclose more about how services like Google’s and Facebook’s digital advertising products worked. The largest companies could be forced to share some data with small rivals. Stiffer competition rules could …
