Dispatches
I read about this show in one of the blogs I check out, but I can’t remember which one unfortunately. It is a British show that as best I can tell does undercover journalism of some sort. This particular show was quite telling, and came under some amount of controversy for possibly being biased. After an investigation (because the police have nothing better to do with their time) it was shown that the show accurately depicted what their research and undercover tapes showed them. So all said I think it is a pretty interesting look in to the radical element in the UK.
Google, being the source of good bits these days has it on YouTube: Dispatches - Undercover Mosque (1 of 6). The other parts of the episode should be under the related videos. If you have a chance you can view it for what it is worth.