This reminds me of "back in the day" when they first started scrambling analog cable (before the digital encryption days). You could go down and buy an old box at the flea market, crack it open, and adjust the little pots to get the signal. It was a PITA 'cause you had to do it just about every time you used it, but lots of people did it.
This was, say, circa 1990. I was in Orlando at the time, and I remember the cable company put together a couple of vans with equipment to detect the receivers in operation (like was said eariler -- same principle as detecting radar detectors). They'd drive around and bust people pretty effectively.
I guess the trick was that even though they only busted a few people, it had a chilling effect.
Chuck