you can unsubscribe to all this rubbish that comes in your mails, as you can for unwanted phone advertising,
see
Beat Cold Callers & Junk Mail: Get free 'no cold callers' sign which they now must obey...
Myself as they have to pay for the return postage I taped one really persistant companies mail (even after I had contacted them to desist) to a heavy section of wrapped scrap timber on which I wrote the next junk mail will be attached to household bricks, put their return address on the envelope and popped it in the post office.... never got another oddly enough... must of took the hint..
heard of people putting used nappies in the mail, but you can get done for that...
then I discovered the links above and signed up...... wont get rid of the yank selling holidays though or the odd one that thinks I would like to do an on the phone survey.......
