Could an enthusiast explain why it is acceptable to listen in on communication which is not public, not addressed to them and by law off limits?
It's not "acceptable" in the legal term. However if you were British, like I am, an many posters on here, you would know what the "British" attitude to such matters is. If it does no harm, is enjoyed by a great many, brings excitement to adults and kids alike, informs people about how things work and makes grown men get out of the house on occasion, we treat it as generally a good thing.
There are always fusspot who like to over react, men (generally men) who need the protection of rules and lots of them. We have just escaped 13 years of more rules introduced into our country than ever before. It is for this common sense reason, that we must allow the authorities to focus on criminals who cause pain, nuisance and suffering. Arresting people who like to listen to ATC, something happily legal in many other enlightened countries isn't a key priority. Why on Earth should it be?
I have had NUMEROUS chats with the armed Police at LCY and LHR with them wanting to know what I am up to, with the camera. Not once in all of those conversations has the readily apparent air band scanner been mentioned even once. Busy men, the Police!
The clinching argument is that it hacks off that poisonous man-child that is Simon Chowder. He who lurks in spotters corner to call other people names. Proud of yourself are we Simon? Run along old thing, mum must have the tea ready by now I think.