This is why I use Sneakemail
"NEW YORK Attorney General Eliot Spitzer has filed a lawsuit accusing a company of selling email addresses in what he described as the largest deliberate breach of privacy in internet history.
The suit against web site operator Gratis Internet alleges that the company sold personal information obtained from millions of consumers under a strict promise of confidentiality.
In each of these deals, Gratis wrongfully shared between one and seven million confidential user records," Mr Spitzer said. "
Sneakemail is an anonymous email service that I have used for years for things such as Web forum subscriptions. It allows you to generate unique email addresses AND record who you have the unique email address to, making it very easy to track down who is selling or sharing your email address. If an email address starts being spammed, simply delete the address :o)