Their commenting database got compromised: http://lifehacker.com/5712785/
If you think you might be on that list, act quickly because right now absolutely everyone has access to your account at any website where you used that same email address and password. Possibly complete list of their sites: cityfile.com, deadspin.com, defamer.com, fleshbot.com, gawker.com, gawker.tv, gizmodo.com, io9.com, jalopnik.com, jezebel.com, kotaku.com, lifehacker.com, sploid.com, valleywag.com.
Edit: Whoops, didn’t see the EE thread on this. This might be a better/easier way to check: