I’ve not really got much to add to what has already been said aside from the observation that the views of people who were there are slightly more nuanced than those who weren’t.
Smart Monkey’s points on Indymedia are also worth repeating:
Everyone I knew on the march actually had jobs. The uniting view was that it is better to get out on the streets and try to do something, even if this results in failure, than to sit behind a keyboard moaning at people waiting for a ready made revolution . . .
Instead of the long list of ‘I told you so’s’ and ‘what did you expect from the police’ with the overtones that we all got what we deserve, it would be nice to have some solidarity from activists even if they did not agree with the march itself. After all it was policed in an extremely aggressive and nasty way (screaming man being dragged about by a broken arm etc.). Perhaps, if you can’t bring yourself to type words of praise for the marchers themselves, you could focus a bit more on the implications of this for wider society.