I saw one parked in the middle of the pavement by Myatt's Field. Literally in the middle, which was a bit odd, because the stand was down and it was locked, like someone had got half way down the road and given up. Or they'd decided to enter the park by climbing over the railings.
Another in Croydon. Two lads, one on an Obike and one on a de-labelled Boris Bike, both barrelling along the pavement in a manner that suggested they'd just nicked something and didn't giving anyone the opportunity to ask for it back , so I suspect it wasn't being used in quite the way the organizers intend.