They actually get some useful information out. The Guy Fawkes masks may be a little over the top or a little too cliche but it's immediately recognizable. Are they an annoyance? Perhaps. Capable of doing anything destructive beyond a little computer hacking? That remains to be seen. But they do get a message out and the message is sincere.
If gunners were as violent as anti-gunners believe, logically there wouldn't be any anti-gunners left.