Facebook just confirmed that a mysterious glitch deactivated the accounts of "a very small percentage" of its users earlier today, ReadWriteWeb reports.

Facebook says the problem was a bug with a sytem intended to detect fake accounts. The company's statement doesn't explain the weirdest feature of the bug, however: only female users were affected.

The bug has been resolved, but Facebook is apparently asking affected users to scan and send a government ID to prove their identities before reactivating their accounts.

It makes sense that Facebook would be careful not to compound its error by turning over control of accounts to the wrong people, but if this report is correct, it sounds like a pretty huge inconvenience, and a step that might leave some privacy-sensitive users a little uneasy.

Here's Facebook's official statement from RWW:

Earlier today, we discovered a bug in a system designed to detect and disable likely fake accounts. The bug, which was live for a short period of time, caused a very small percentage of Facebook accounts to be mistakenly disabled. Upon discovering the bug, we immediately worked to resolve it. It's now been fixed, and we're in the process of reactivating and notifying the people who were affected.

And, via Boy Genius Report, the email affected users have received:

Please upload a government-issued ID to this report and make sure that your full name, date of birth, and photo are clear. You should also black out any personal information that is not needed to verify your identity (e.g., social security number).

If you do not have access to a scanner, a digital image of your photo ID will be accepted as well. Rest assured that we will permanently delete your ID from our servers once we have used it to verify the authenticity of your account.