The World: New York - NBC forces YouTube to pull Obama campaign ad

YouTube, the Google-owned video sharing website, has been told to pull a Barack Obama campaign ad following allegations by NBC that the spot featured copyrighted content that Obama's campaign team had not been given permission to use.

Titled "bad news", the ad featured footage of NBC's Tom Brokaw and MSNBC's Keith Olbermann, without the network's consent.

Meanwhile, research has shown that Obama's ad campaign around the recent presidential debate was far more aggressive than that of rival John McCain, in terms of purchasing ads tied to debate-related search terms.