I know what you're talking about. I was also a mod myself on /r/Suomi (Finland) and quit after a rather serious incident. Other mods and users on far-right subs started to compile a list of European subreddit moderators whom they deemed 'SJWs' and tried to gather as much personal information on everyone. Someone from that group leaked the documents to us and it was quite alarming. The scale, effort and hate that went into those documents was the most surprising thing.

Anyways, when our main mod got approached on the street and asked if he was /u/nickname on reddit and he replied yes, he got stabbed. That was the day I quit.