I read about something he did that pissed me off. He actually turned one of his "guests" microphone off and told him he doesn't care what he has to say and later he even threatened to hit the guy.
Boy if I was that guy my breaking point surely would have been when he turned off his microphone and thus couldn't be heard. And if I was that guy when O'Reilly threatened to hit him I'd say bing it on asshole because you'll get the asswhipping of a lifetime!
Before I read that, I kind of liked him and thought his show was entertaining to watch. But when I read that he definately seems to be a thug. An old, grumpy, bully of a thug! When I read that I lost all respect for him.