Mike they do what is supposed to be illegal, known as IP tracking. In fact, once you're connected every single information is recorded. Dont forget the first thing you do after purchasing a computer is to enter your personal data… Even a change of the HD won't cure that.
Surprisingly My Lady is back from London I'll ask her how to avoid at least IP tracking…
You will be suggested to use Tor or to start your purchase at home and finish it at your office. Not very much helpful in your case!
