G20: 'Protester' dies at Bank of England camp

The Sky News clip quoted is inaccurate. It gives the impression Ian Tomlinson died at the Climate Camp G20 demo, whereas in fact he died within the police 'kettle' (cordon) around the G-20 Meltdown demo at the Bank.

As yet its unclear whether he was a victim of the police brutality:

Pictures seen by the Guardian, and corroborated by witnesses, suggest that Mr Tomlinson initially fell to the ground by a window of 11 Royal Exchange, outside the Mont Blanc shop, in front of five riot officers.
A subsequent picture shows him being lifted off the floor by a protester.
Seconds later, he is seen walking past a line of police dogs. He is believed to have collapsed again close to the junction of Birchin Lane, near a Starbucks and Office Angels.
Jackson said Mr Tomlison was then surrounded by police officers who were pelted with at least one missile.
"There were a couple of people throwing bottles in that general direction," he said. "But they were told to stop doing that by the crowd. In fact, some people in the crowd threatened to kill them if they did anything to disrupt the treatment."

source: The Guardian