Just to be clear about who has legal powers for controlling the misuse of frequencies. It's not the CAA.
It used to be the RCA (Radio Communications Agency). I worked with them a few years ago tracking down an oik who'd stolen a radio and thought it great fun to be a bedroom air traffic controller.
He was located using RDF and 'spoken too' by a big chap in a uniform.
THe RCA was absorbed by OFCOM. The CAA collect radio licence fees on behalf of, in effect, the Inland Revenue, but the only powers they have under the ANO in this instance would include reckless endangerment.
Hope this clarifies the position as I understand it.
Sir George Cayley