It's one of the dangers of moderating on the Internet. Back when I was doing it, I had to deal with everything from death threats to foreign police (suicidal users) to white supremacists to the FBI (bomb threats) on a fairly regular basis. It's proportional to the size of the community and how strong the social expectations are, but the interconnected nature of the Internet means that you'll get drive-by attacks just by being accessible. I know more than one mod that had to resign their duties/accounts because someone started stalking them across other platforms and in real life.