Whenever people start doing this on a list I am on (obnoxiously post off-topic messages) I take their addresses and use them when I am required to supply registration information on a website. Of course, I _also_ check those nasty little check boxes like "Send me email announcements and news".
It is the only thing that makes putting up with inconsiderate people bearable - petty revenge, that is. Of course, I am now going to have to do this for my own address...but it is worth the sacrifice.
