I'm a huge fan of promoting cycling (see my previous posts) but I can see why people hate them. Recently have been on the receiving end of a lot of stupidity, but the main culprits are a bunch of teenagers that fly along the south bank at a stupid pace. I don't go out that much, but I've see the same group causing far to much in a short space of time. Last month I saw them causing nuisance by the clink museum, last week chucking eggs when cycling past the Starbucks by tower bridge, and today in potter fields playing chicken with tourists. I'm fairly certain they are they same group each time. There are five of them, each time playing chicken with people coming in the opposite direction.
Given the number of small children in the area, it is just a small step from disaster.
Why don't you call the police David instead of writing to a forum ? It seems quite illegal ... It is not a new thing. In summer time they come out and take a street and go back and forward. I remember same complains in another thread last year. Just call the police and they will take the bikes if illegal.