"I got dirt on you, doggy!"
Pac and Biggie... Nas and Jigga... Bill O'Reilly and every rapper who has had some commercial success. You can't exclude O'Reilly from battle rap, he is a heavy-hitting contender in the hip-hop arena. Remember when he insisted that people boycott Pepsi products because Ludacris endorsed it? Luda got fired the next day. Bill-O even tried to interrupt his holiness Cam'ron and Dame Dash; at least we got a pretty decent meme out of it.
O'Reilly's most recent attack was on Lupe Fiasco for claiming that President Obama - and all previous Commanders-In-Chief - are terrorists. In a matter of three days, O'Reilly called Lupe a pinhead, invited him on the show, and "debated" with him for five minutes. Of course it wasn't a true debate; not much can come from a discussion with someone who interrupted the President almost 50 times in an interview.