Don't feed the troll
In internet speak, “to feed the troll” means to try to engage people online who are just trying to stir up discord for no other reason than to provoke people. Trolls are almost always insecure, psychologically-damaged people, if not full-blown psychopaths who lack the usual social barriers that most of us possess. Thus, a common piece of advice tossed about on the Internet is: “don’t feed the troll.” This is sound advice.