Excellent video. Have posted the link on a forum dedicated to gettign our pistols back... and unofficially with a strong RKBA contingent.
It seems the protest was the one against the (then proposed) Hunting With Dogs Act. This was one of the largest civil demostration the UK has ever seen, if not the largest. Police 'arrested troublemakers' during some of the march, though there have been many people claiming the first blows were from policemen in full riot gear -- kevlar, shield, weighed gloves etc. The Act has been law since 2004. (To be perfectly correct though, this was concerned with an only marginally connected topic of hunting foxes from horseback with packs of hounds. Some sensible people connected with both areas though. There are good arguments why the ban should not have been made law, and a lot of very unintelligent and illogical arguments against foxhunting. The ban is regularly flouted, and antihunt protesters often physically attack, injure, spit on, make false accusations against huntspeople and their animals. The ban was pushed through by a government getting a bee in its bonnet about a topic, the tabloids doing a five-minute-wonder about 'We must ban these eveil people from killing our sweet cute foxess!!!!!111111oneoneone' etc. and the general public, the topic affecting less than 95% of them, being convinced by much emotional ind misleading rhetoric. Hmmm, sounds familiar...)
My impressions are that most people in the UK are sympathetic or support home defence etc. and appreciate that crime (esp. violent crime) is up. They don't, however, realise that they are in favour of RKBA. Blame the mass media or whathaveyou if you want; I mainly do. We have so much 'political correctness' and the Powers that Be ramming certain messages down our throats ('Crime is down!', 'production of boots is up!' 'Oceana has always been at war with Easasia!' etc.) that I think most people are prevented from putting two and two together... or being told that to think '4' is wrong.
I think that the British firearms communities have finally learned their lesson though. It's been a long, slow and damned painful one, but we now know what a wedge is dagnabbit... and we understand inclined planes very well too. We're trying to rally round. Our shooting groups are very fragmented and quite introverted. Our NRA is mainly interested in shooting .308 bolt-action rifles at Bisley Ranges and is quite... cliquey. Sporting shooters are by-and-large happy so long as they get adequate tools of their job/sport, and so are happy with the status quo. RKBA loby is... limited. 'Alternative' represtentative/pressure groups have been created, notably SAGBNI, but they do not have the size, age or muscle of the establishment. This is the reason why we're looking to combine the largest target-shooting groups and any others which wish to under one banner. This will hopefully allow us a unified front from which to fight, economies of scale and amny other benefits (including legally required consultation on legislation affecting us). Divided we stumbled; together we will rise again.