Is there something I can do about a corrupted FC?

[WinterLuna]

I once had someone say horrible and untrue things about me and my FC to pretty much anyone he could talk to. I saw it myself, and had around 3 other friends tell me about what he was saying. I reported this to a GM and they couldn't (wouldn't) do anything about it because A) I couldn't provide exact proof because I didn't document the date and times and B) a lot of the information was second hand.

I was pretty salty about it for a while but I appreciate the GM's don't have the time to find all of this information themselves. Unless you have exact proof of this happening and have experienced it personally, I highly doubt you can do anything.