Facebook Loses Users' Email Notification Settings

I got this in my email from Facebook.

Unfortunately, the settings that control which email notifications get sent to you were lost. We're sorry for the inconvenience.

Wow. Really? I agree with what M. David Peterson had to say about the issue. Sounds like they've got some inexperienced engineers running the show.

If this had been a web service with critical data that wasn't backed up, people would be pretty pissed. When I went to check my email notifications settings, however, everything seemed to be intact. What gives?