How to remove your Magento account
You cannot delete your Magento Go account. However, you can request account removal by posting a message on the forum: http://www.magentocommerce.com/boards
Or use the contact form found here: http://www.magentocommerce.com/company/contact-us/
If you use the contact form, please provide them with your account details (account ID, email address) together with a brief message that you’d like to have your account fully removed.
Helpful Trick: Obfuscate your profile info.
Because most accounts and profiles at Magento cannot be removed, we suggest you login and change your account and profile information altogether.
Make sure you are logged in to your account on the site and click on the profile or options settings. Locate the fields with your personal info (email, name, address) and fill in generic, random information instead. If you can only select from several fields, change anything personally identifying. If possible, use a homepage/URL field or long text field (such as Description) and put this line in it: http://remove.org/removal-requested. This may encourage webmasters and admins to create an easier removal outlet.
Helpful Trick: Removing online data
Helpful Trick: Remove third-party logins
If you signed up for Magento using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Magento. Click here to find out how.