If you are an ATCO in the UK not wishing to be eavesdropped on, fine, but don't go to work abroad as it appears to be legal in most countries. The liveatc.net site doesn't have any feeds from UK airports and says that's its because of the law. I am not aware of any other countries in the West with a similar law. I can legally listen to many ATC transmissions from abroad on the web but not UK ones on a radio.
Then again most countries have a few laws almost unique to themselves some quite logical.