Hi Andy, the Crown Prosecution Service website reported a case  - R v Hemingway - heard on 15 November at Leeds Crown Court where the defendant pleaded guilty to uploading 5 racist videos to YouTube, contrary to s.21(2) Public Order Act 1986. He was sentenced to 15 months. Some of the videos were calls to violence against black people living in Dewsbury where the defendant lived. The material was originally discovered by journalist doing research on Dewsbury. There are more details about the case in the Hatred Offences section of RaceActionNet here.
Do let us know about your work on the use of social working sites. This case seems to have arisen somewhat by accident - and the defendant was tracked down following a tip-off to the police after a CrimeStopper advert in the local paper.

hi paul please see my other post if this is of interest to you maybe you are free on tuesday to attend the first imput session

regards ian