I was chatting to a colleague about this the other day. Plagues of them everywhere. Hardly any of the riders wear helmets, they whizz along far too fast, don’t signal, don’t slow down to turn corners, dump the bikes in huge amounts blocking pavements.
I saw one ride cycle full pelt through crowds outside Monument station and straight out onto the cobbled road without looking (I don’t think she can have realised it was a road) and then straight through the red light at the bottom. I’ve had so many near misses and haven’t had one near miss with a car.