Estimates of attendance range from 250 to 1000. Long-winded off-topic propaganda was not censored:

If an Iranian communist or anyone else, wants to talk about freedom of expression at a rally in London, then I am happy to listen, but the moment they start talking about Guantanamo Bay, US foreign policy or 'just' economic systems, which are NOTHING to do with the issue at hand, I will quite bluntly thank them to stick their views where the sun does not shine.

During the week prior to the rally there was some equivocating about whether to show the cartoons which were supposed to be its raison d'etre:

Initial plans to print the controversial cartoons satirising the Prophet Muhammad onto banners as a way of expressing support for the Danish cartoonists were shelved. "There is no way in the present climate that they could be construed as anything other than a potential threat," said Mr Risdon.

Police said there had been no arrests but officers did receive a complaint about the message on one protester's placard. A Scotland Yard spokeswoman said officers spoke to the man and he was later allowed to rejoin the demonstration. "The complainant stated they felt threatened by a placard they believed depicted the Prophet Muhammad," she said. "Details of the complaint, together with evidence gathered by police are to be passed to the Crown Prosecution Service."

But everyone seemed to unite when the police made a move to confiscate them.

It was announced that the police had stopped someone expressing their views! There seemed to be some sympathy for the position of the police from the podium as the “offender” had dared to show some of the cartoons. The Iranian speaker highlighted this fact to the audience and suggested that the offending cartoon be distributed from hand to hand amongt the assembled as the police could not arrest everyboady! This was done with relish. The cartoon was passed from hand to hand by those who wanted to defend the cause of freedom. Solidarity was shown with the person who had been victimised. Eventually the cartoon seemed to “disappear”.

This guy was not impressed.

There was also some kind of legal prohibition against waving flags (!) (which had never been enforced for any other political rally; funny thing about that), so people wrapped their Danish flags around themselves as shawls.

UPDATE: More photos - including inventive and humorous signs (via Samizdata comments): here, here, here,
here.