As violence spiralled during last summer's "Reclaim The Streets" protest, hundreds of screaming rioters rampaged through the foyer of the Liffe building and tried to reach the rest of it. Security staff and other employees barred their way, braving stones and flailing fists, the court was told. One trader was given a bloody nose and a distress flare was thrown, filling the area with smoke.
Janet Weakes, for the prosecution, said a photograph of the demonstrators trying to "surge" through the human security barrier was printed in the Daily Telegraph. Ms Weakes claimed it showed Anthony Jones, 35, in a distinctive T-shirt, about to throw a punch. He was still wearing the T-shirt the day after when a policeman recognised him from the picture and arrested him.
At first he gave a false name, then said he had been swept into the building with the "tide" of people. He said he had been defending himself and "at no stage threw any punch".
Mark O'Connell, a maintenance technician, said he was in the building with other employees. "We tried to assist security staff holding the doors back, but when they started to smash through the glass we made a rapid exit." As the pushing continued, he saw Mr Jones clench his fist. "I saw the fist being raised out of the corner of my eye and instinctively put my arm up. He didn't strike me."
Mr Jones, of no fixed address, denies violent disorder. The case continues.