It’s common in communities where rigid adherence to a set of beliefs is necessary to enforce cohesion. It’s commonly used to avoid engagement with “Facts U Dislike” (haha) by terminating all meaningful discussion.

Part of a flat earth forum and you’re posting an experiment you performed that suggests the earth is round? You’re spreading FUD that should be ignored.

Posting on a crypto shitcoins discord about how this kinda looks like a scam and maybe it’s not a good investment? That’s also FUD. You’re just mad that everyone else is going to be rich.