Indeed, and thus I stand by my original point, though downvoted! The UK Wireless Telegraphy Acts made it illegal to listen to something that you weren't meant

Indeed, and thus I stand by my original point, though downvoted! The UK Wireless Telegraphy Acts made it illegal to listen to something that you weren't meant to by fiat without need of any proof of harm AFAIK, so there could easily be random laws in various places outlawing this extraction of power that has to be made up by other generation, even if small. You generally aren't allowed to extract even small amounts of power from the system unmetered with a wire either, without specific permission.