According to the AP, the Pope is open to social netoworking sites like Facebook, but warns against their possible evils. While they can help to foster understanding they can also "isolate people and marginalize others." He also worries that some can become obsessive about the sites. Basically, the Pope doesn't want you to be an online asshole, or pale internet geek (All in all, sound similar to the gospel of former Gawker editor Jessica Coen). And of course, he doesn't approve of any naughty nonsense.
So remember. If you use Facebook, don't become isolated. The man who is regularly paraded around in a bullet proof glass cube commands it.