Whether they are Marxists, unemployed crusties, members of the WI, students, members of the animal liberation front, or undercover police, is neither here nor there. They were there as anarchists, and not as students. The march was about student fees not anarchy. I'm not against anarchy per se in fact I'm broadly in favour of anarcho-communism myself, though I tend to think people looking for a bundle will wave whatever flag suits their purpose.