The part about "Facebook sneaking through contacts and adding friends' numbers" isn't correct: the Facebook app has always had a pretty clear description about what would happen if contact sync (an optional feature) is enabled.

For example, on iOS, it looked like this almost two years back: http://www.neowin.net/images/uploaded/iPhoneNumber.png (as seen on this page from October 2010: http://www.marismith.com/facebook-phonebook-how-safe-your-ce...) I don't have any old screenshots of the Android version, but the current app is similar to the iOS screenshots above.