I actually had this happen for a while. For some reason it stopped. I still have no idea why. I use vpn and alias emails so one or a combination of both is the problem. After some time, maybe I got my trust level up.
Actually, I didn't know this before. I knew for sure it wasn't allowed in the workplace or at school but didn't know it was an actual federal law. Thanks for pointing that out.
It's legally protected speech. In real life, you would get the shit knocked out of you, and rightfully so. In online, the most they can do is virtually beat them up or ban from the servers.
Edit: it depends on the severity of it too iirc. Saying "nice tits" isn't as severe as "I'm going to rape the shit out of you"