Always be careful of adding applications and what information you are giving....
FACEBOOK - no doubt is fast growing social networking website, which let users to add applications to their account to have bit of more fun while using their account. Unfortunately, most of the users doesn't even read message and just install application which could reveal their personal information and could affect their privacy information.
Detail information was recently published by Dshield handler John Bambenek in his recent post.
See: Facebook, pr0n and privacy