This is absolute b*llocks!
The whole world knows Brits are the softest when it comes to protests and demonstration. Just because Chinese police is seen as human right violator doesn't mean you'll blame London Police.
In fact, I suggest you ask ANY CHINESE living in the London what's happening. They will tell you that it's couple of hundred 15-16 years old [Not old enough to press changes against] chavs who have taken the whole city hostage.
Do you even know why are they doing it? Actually there's no reason behind it! They just think they're too hard. And they think setting alight police vehicles, cars, buses, buildings, peoples' businesses, shops and public property is 'COOL'.