I did some searching and found a FoI request asking how many investigations and prosecutions have been made so far under the 2006 Act. The answer was three investigations, but that covers the entire spectrum including police, armed forces, etc. Also, OFCOM made excuses and declined to say how many prosecutions, or even successful ones, had resulted, which leads me to think the answer is close to or at zero.
Listening to ATC at home? Technically illegal but probably alongside walking on the cracks in the pavement as something that would actually go to court...