But that is irrelevant to this topic as they are illegal so the police have powers to prosecute.Legal e-bikes are limited. There are huge numbers of unlimited e-bikes operating in Bristol. Some of the motocross-style models are effectively electric motorbikes rather than electric bicycles. They are that fast.
I have seen a scary fast one near me, must have been doing 35 mph, rider with no helmet, wearing a hoodie. It’s just the same with motocross bikes, no number plate, no insurance & rider with no license etc.