if someone is being impersonated on the #fediverse how do they find out?
sure you can search for user names, but doesn’t help with impersonation on defederated servers right?
any way to search the whole thing or have all the projects aiming to do that stopped because of backlash @ the idea of a fediverse-wide search function?
That’s not specifically an issue for the Fediverse but your entire online life. You may consider a service like Keyoxide.
Edit for an addition: I just noticed that this doesn’t answer the question. Keyoxide helps to protect against impersonation, not how to find out whether that already happens. I don’t know of an easy way to do that, though. You’d probably need to do a lot of research across the web I guess?