I was in the Rotherhithe tunnel the other day, and a guy on a moped stopped his bike halfway through the tunnel, got on the pavement, rode down the pavement past about 5 cars (presumably at about 30, since the cars would have been doing 20 (average speed cameras)) then pulled back onto the road. I genuinely couldn't believe my eyes...
Once almost got hit by a moped on a pavement, which allowed cyclists. I commented to the young chav who turned around and started arguing that he wasn't on the pavement and did I want a fight, even disputing when an old man confirmed it.
My response; sure and I took my phone/ camera out to take a photo. To which he quickly raced off using the road.
On the other hand, being in Cambodia when there is a traffic jam, hundreds of mopeds jump onto the pavement with little regard for peds.