Privacy Issues with some apps and now by default New Instant Personalization shares you personal information with a other websites. The way to opt out of this takes a bit of digging and is not intuitive. Because if you opt out of it your friends can still share the information they have on you.
OK HEAR ME OUT! This site is not intended for children under the age of 13. with that noted, you cannot say you do not want your 7 year old on this site, that is useless, as it is illegal to sign up unless you are 13 or over.
Also, external applications are your choice on weather you use it or not. you are not forced to use applications, I do not use applications myself, and find the ones that allow computers to post on your, and other peoples walls most unlikeable, for most(/all) of the posts are spam (again, you choose if you use the application). However, you can remove the posts on your wall, and you can remove wall posts that were made from your profile, which includes the ones from applications.
With that said, this is a good and safe (as you let it be) site.
ALSO IN RESPONSE TO PEOPLE WHO COMPLAIN THAT YOUR PRIVACY IS NO LONGER EXISTENT; you put on Facebook what you put on Facebook, if its private then DO NOT POST IT I REPEAT, DO NOT POST YOUR PRIVATE INFORMATION, and no worries about your private info being released. simple. (why don't people on this site understand that....?
@Memorians; they do not sell your information, they pull info to make the experience better, like how farmville uses friends profile pictures and names so you can be neighbors w/ them. and the pic is for good measure.(hit the period button hard to emphasize point.)