https://mashable.com/article/facebook-50-million-accounts-hacked/

This says there was a security issue that potentially affected 50 million accounts, with the troubling statement that they saw the issue being exploited "at a fairly large scale".

With decentralized social media, I don't think this same class of issue could even happen. The failures of one instance do not have the major effects that the failures of Facebook and other centralized platforms do, as it's simply one node in a sea of nodes. Only the people on that instance are at risk, and the more spread out we are the less at risk the community as a whole is when an instance is hit by something like this.

Trusting your livelihoods to centralized social media is a mistake.