Dogtrousers
Kilometre nibbler
Not surprising as central London must represent really low-hanging fruit if you want to find illegal e-bikes.
Wander through Soho and you're almost guaranteed to see people zipping around not on bikes that have been modified, but purpose-built e-motorbikes with huge fat tyres. Actually, given the congestion there they can't pick up much speed, and they can't use the pavements because they are too small and crowded so they aren't any more of a nuisance than the rest of the traffic. But they are definitely noticeable.