Someone named Tracy who runs a show at Blog Talk Radio (blogtalkradio.com) called No Compromise Radio was conducting an interview of Phil Berg two days ago about the Obama/U.S. citizenship issue. She was 13 minutes into her show when BTR pulled the plug, apparently claiming that her show was:

racially or ethnically offensive, defamatory, unreasonably violent, threatening, intimidating or harassing; 2. contains falsehoods or misrepresentations that could damage BlogTalkRadio or any other person;

Details here. I'd tend to think that Berg would avoid doing anything listed above, although I wouldn't be surprised to learn that someone who doesn't appear to be that lawyerly-inclined might have crossed the line. BTR may have justifiably pulled the plug in order to protect themselves, they might have over-reacted, they might have unjustifiably responded to contacts from BHO fans, or they might be in the tank for BHO. Others are welcome to contact them and ask for the details.