One of the major points that Facebook scored over all of the other social networking sites, at least initially, was its stringent privacy settings that gave you a sense of security and safety regarding the contents of your profile on Facebook.
However, with the advent of Twitter and other such sites, Facebook might be in a mood to keep up with the growth of its competitors - and this might be why now Facebook content is easily accessible to strangers and gone are the days when you had a sense of privacy that only you and your exclusive friends shared on the network.