In the early days, when TVs were badly shielded and (more importantly) few and far between, and where radio transmitters were rare, it's plausible that simply l

In the early days, when TVs were badly shielded and (more importantly) few and far between, and where radio transmitters were rare, it's plausible that simply listening for electromagnetic noise would yield usable results. Today, to believe that a machine exists (in secrecy, no less) that can detect from a considerable distance, through walls, if someone is watching live TV (watching non-live TV without a license is legal) on iPlayer on their computer in a setting overflowing with all sorts of legitimate electromagnetic radiation is, frankly, laughable.