Kickstarter has revealed that they experienced a hack over the week. No credit card information was compromised, and they immediately worked to close the security breach.
Why tell us a few days late? They pursued a thorough investigation first. They verified two accounts were compromised, and identifying information, such as usernames, email addresses, mailing addresses, were accessed.
Again, we would like to emphasize that Kickstarter closed the breach ASAP, and investigated the matter fully before disclosing it to the public. Kickstarter recommends you change your password. If you use Facebook, that login process was not compromised and they have reset it for you so you need only log in again.