If you want to get paranoid, check out Van Eck phreaking. In reality, experiment when riding a lift in the middle of a large building, doubt many radio signals will get through there.
Even when your suggestion is highly sophisticated, I'd rather stay non-paranoid, which itself is often just a description given by others and at that time not an actual condition or mental state. Anyway, I would certainly be interested to read about new studies related to Van Eck phreaking (or similar). Google-search revealed mostly the same old stuff that were there years ago.
I'm sure that signal processing and abilities to adjust signal-to-noise -ratio have generally developed upwards since 2006 (or something).
I'm sure that signal processing and abilities to adjust signal-to-noise -ratio have generally developed upwards since 2006 (or something).