For a while, you'd be asked for your post code when buying TV equipment (UK). Whilst it wasn't a legal requirement to provide, a lot of places would be really awkward about it if you didn't. I took a small amount of satisfaction in providing the Downing Street post code.

It's now no longer an issue as companies aren't required to ask for and forward that data to TVL so they don't ask (and I'm probably ordering online so they have it anyway).