ClovisMan
There were indeed some headline grabbing placards at the demonstration, but from what I understand it was largely a demonstration about the plight of fellow Musims in Syria. Given that the UK has a considerable indigenous Muslim population, I see this as just a specific group of people exercising their democratic rights of protest and free speech.
The YouTube link you posted appears to be putting a heavily Christian spin on the story. although I did not watch the whole clip) The call for a Caliphate was for Syria, not UK as was implied.
Personally I'd prefer not to see this sort of demonstration on the streets of London, but its the price we pay for democracy.
A balancing report of what I think is the protest referred to in the clip.... albeit from the Daily Express newspaper!:
http://www.express.co.uk/news/uk/745056/...ndon-Syria