From Facebook Developer Wiki

Facebook Connect-motivated feature request:

• Motivation: If my site has a user account that is linked to a facebook account, and if the user chooses to initiate disconnection from facebook through my site, then, during disconnection, I can provide the user an alternate way to authenticate themselves and retain access to their account (since they were previously using facebook to authenticate). However, if they initiate disconnection through facebook.com, then my site can't authenticate them anymore and the user can never access their account again. (My site might never have collected a username and password for them.)
• Feature request: When a user de-authorizes my application through facebook.com, give me a chance to warn them that they will never be able to access their account again and that they should instead disconnect through my site.

419214 14:54, 20 December 2008 (PST)