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).

I generally use webmaster@[their domain] so they get the SPAM instead of me.

It's not legal? What part is illegal?

When a website offers you a quote about water fountains/new printers/whatever, I doub't it's legal to say that you're company X and that you'd be interested in this particular quote.

I'd be interested in seeing a specific law or case where that sort of thing was illegal. Lying by itself isn't illegal (in the United States at least, i dunno about elsewhere)