[ezconnect]

I think the British also invented a way to discover non paying public TV broadcast receiver driving around in van with the equipment.

[mike_hearn]

Supposedly the detector vans were a myth. A few appear to have been built, but they were essentially useless after 1950 as the interference from car ignitions started to become more of an issue. But the public didn't know that and the idea of it worked wonders for compliance. The BBC ran campaigns that implied huge fleets of them, but maybe there were only a few in reality.

At some point the BBC were forced under FOIA to admit they'd never prosecuted anyone using evidence from detector vans.

[actionfromafar]

Maybe THAT is the reason why there is so much hush-hush about the detector vans?!

If they used a technique which essentially was considered military secret not too long ago. (Compared to the time when the vans started to appear.)