Just to share

1. While signing up for any new website enter your Gmail address as your_user_name_+_website@gmail.com.

2. Don't worry, you will receive the mails as usual because Gmail doesn't recognize any combination of words or numbers after the "+" (which can also be replaced by ".") sign.

3. Whenever you get any spam message just click on the "Show Details" link to expand the email header and find out the email address to which it was sent.

4. If you had signed up according to the step number 1, you will be able to find out which site gave your email address to the spammer.

Use this to find out which websites are selling your email addresses, check out their privacy policy and sue them if they lied.  If you found this useful, don't forget to share it with others.