Social Networking: A purposeful loss of privacy

In today's world, Social Networking is a large part of everyday living. We dedicate so much of our time to these websites (such as Facebook, Twitter, etc) and virtual relationships that we somewhat lost our 'relationship' with ourselves. We can access them in any location, at any time; through our mobile devices, computers, media players, etc. Can we really admit that there is as much privacy now-a-days as there were prior to the launch of these sites? Although we do not need to share our thoughts, age and relationship status with our 600+ 'friends', we all tend to do so, regardless. I would like to find out who really owns the information that each individual posts, if that information can be archived, and if it can affect our future (particularly the employment area). Many articles have been written, in the NYTimes, Forbes, and many more, about this issue and how it has an affect on individuals.