Do you not remember Bryan Craig telling that fan he would find him and break his #$^%*! fingers? TPTB forced him to apologize. But that started with Bryan's mother sparring with fans and BC stepped in to defend his mom. I saw it all happen and I can assure you that his mom gave as good as she got!
The reason why I say the onus is on the celebrity here is what they post is pretty much PERMANENT. Some of these fans are like the CIA. They screenshot things at lightning speed. And I would imagine that Disney/ABC would not be happy if a dust up went too far and now the actor is in hot water. Joe/Sally Troll will go about their day. The celebrity has followers and are in the public eye. It can and has left a blemish.