Emil Tiades wrote:

Of course, if a member of the public was to clout one of the little
turds, the police would appear within seconds and charge him with
assault, with plenty of do-gooders being witnesses for the
prosecution.

I went to the police recently to report some problems, and the police
said that without being able to formally identify the offenders there
was little I could do. I said, OK then, I'll photograph them with my
mobile phone. They told me not to do this as in principle it could leave
me open to being prosecuted for being in possession of photographs of
minors.

It just seems like you can't win.