This begs the question, "How did they organize the protest?"

Wales News: Anarchy in the UK as G20 protestors set to march:

AN ARMY of anarchists is set to march on London’s G20 summit, to vent their anger at bankers.

Thousands of activists are expected to travel from all across Wales to the capital, to coincide with the meeting of the leaders of the world’s 20 most powerful economies in London this week.

Among those travelling up to London is Ian Bone, once dubbed “the most dangerous man in Britain,” who rose to prominence in Swansea in the 1980s.

The 61-year-old, who founded anarchist newspaper Class War, said: “There will be hundreds, thousands, of anarchists pouring into London from Radnorshire to Powys, from Brecon and elsewhere. There will be a lot of people from Swansea and Newport.”...