The xkcd forums are currently offline. We've been alerted that portions of the PHPBB user table from our forums showed up in a leaked data collection. The data includes usernames, email addresses, salted, hashed passwords, and in some cases an IP address from the time of registration.
We’ve taken the forums offline until we can go over them and make sure they're secure. If you're an echochamber.me/xkcd forums user, you should immediately change your password for any other accounts on which you used the same or a similar password.