“My understanding is the cable companies have been catching signal theives for years with the IF stage detection trucks.”
That’s why I wrap my entire house in tinfoil. Aside from keeping out the Venusian mind control ray, it keeps any pesky IF radiation in.
I found it easiest to get the oldest, therefore IF leakiest, TV going all the time with “Leave it to Beaver” episodes. It’ll drive them NUTZ.