Apparently there was a march from Trafalgar Square , "via Downing Street" (how, exactly ? - the gates are shut !) ) to New Scotland Yard today, i.e. right through the heart of the SOCPA Designated Area around Parliament Square, to protest about the violent policing of protests and demonstrations.
The left wing organisers, who appear to be drawn mostly from the manipulative Socialist Workers Party and Bob Crow's left wing RMT union, calling themselves United Campaign Against Police Violence seem to have a web blog, but there really has been almost no publicity about this event.
Even Indymedia UK do not seem to have any coverage of it, although there was a brief mention on Sky tv News.
The Palace of Westminster is also mostly empty today, a Saturday during the Whitsun Parliamentary recess, so the politicians and journalists of the "Westminster Village" will have ignored this demonstration, in favour of the "MPs expenses scandals"..
The issues they are nominally protesting e.g. "justice for those killed in police custody and for the right to protest" should really appeal to peaceful, democratic people across political party lines, but this protest seems to be a left wing / anarchist "closed shop",
This is a shame, because many other people are also furious and dissatisfied about the G20 demonstrations policing tactics, the death of Ian Tomlinson, the pre-event police surveillance and media hype about "planned violence".etc.whilst Prime Minister Gordon Brown tried, and failed, to convince people that he was somehow leading the international efforts to solve the world banking crisis, which he was personally partly responsible for.