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There were also plenty of cops. They had talked to a few people as the ride met up at Waterloo Bridge and were seen handing some kind of paperwork to the owner of one of the sound systems, but no sign of any significant attempt to curtail the ride. Far from being oppressive, they kept themselves to themselves on the whole.
I personally got a quite pissed off a few times by seemingly inconsiderate behavior from the ride itself - for example, not letting pedestrians cross the road. In another example, a bus coming in the opposite direction was blocked by cyclists on the wrong side of the road and held up for at least ten minutes as a result.
The cops did grab a few idiots and give them some stern words on several occasions throughout the ride for cycling on the wrong side of the road into oncoming traffic.
The police made fools of themselves at Parliament Square when they tried to block the rides third or forth rotation around the square and ended up stalling the ride there for a good half hour. The ride would have moved off much quicker if left to it's own devices as the ride likes to move and becomes impatient when people stop.