This past weekend the Gawker Media servers were compromised and 1.3 million login credentials were stolen. While the passwords were encrypted, the method used wasn't the strongest. The end result? At least one-third of the passwords have already been cracked, and some believe that another third can feasibly be cracked as well.

Much of the advice circulating around the Gawker attack has revolved around changing your Gawker Media account passwords. And this includes not only Gawker.com, but also Lifehacker, Gizmodo, Jezebel, io9, Jalopnik, Kotaku, Deadspin, and Fleshbot, as well.

However, that advice ignores the real problem: the fact that these sites require your email address be used as your username.

Sure, you could set up bogus email accounts for each online account you use, but that's a pretty cumbersome workaround. So in very, very many cases you will find that the username is identical to one used on other sites. And that's really the crux of the problem.

Twitter wasn't involved in the compromise. However, because Twitter also requires an email account to login, the attackers don't need the Twitter username to break into those accounts. If they know [email protected] has password123 on Gawker, then they can use that same [email protected] to see if they have a Twitter account. And if they do, they can then try the same password.

The username should serve as half the account security. Instead, forced practices by many online providers cripple that half and leave the password as the only barrier to entry. In my opinion, this is the real weakness the Gawker Media compromise reveals.

Mary Landesman is an antivirus professional and senior security researcher for ScanSafe, now part of Cisco. In 2009 she was awarded a Microsoft MVP for her work in consumer security.