Something does not feel right about this; Facebook owns it all if it is on their site?
Read their terms yourself, and make up your own mind. How much content do you want to give to Facebook in the name of collaborating with friends?
Perhaps on the flip side, in a connected world, ownership is always transferred to those who own the networks (think about how the NSA spies on US citizens or how emails we write at work are owned by the employer). Is Facebook really doing anything different?