And people wonder why certain people have become paranoid about remaining anonymous online these days.

The sort of signaling they're talking about is pretty standard. They're trying to figure out what to use to find what they want, which is potential hateful people. The use of things off-platform is possibly what's most concerning. The whole thing is not exactly surprising, other than using things off-platform. It's probably similar things that they look for in regard to trolls though. They just decided to spider the entire web to eliminate certain people from their platform. They don't want anyone that matches their signals on their platform, even if they don't really even use their platform.

The thing is, these people don't get a trial or anything. They likely won't ever even see the evidence against them.