They just send out demands to everyone without a license on the basis that you must have a TV.

Actually, I got a letter like that just a few days ago. It stated that i should go pay up if I have a Radio and/or Color TV, otherwise they will come visit some time this spring.
I don't have a TV (I *do* have a video and a projector but... that's not a Color TV, right? ;-), and I don't ever listen to radio. If by some freak accident I actually watch TV, it's not DR1 or DR2 (similar to BBC, they get 98% of the revenue from the tax (~300 Euro/year/household), no ads, but there's TV-shop on DR2 at night... yuck!).

At least here in Denmark, there's the nice little legal twist that if they come check me out, I am not required to let them in unless they have a court order and a cop with them.

Regardless, I'll probably swap the Reciever with my Amp/Preamp combo and stuff the video and the Surround Reciever in the attic, just to be 100% sure.