FB should be Asur for everyone bechol Loshon Shehu, it is the absolute biggest danger for a frum yid, even lehavdil for goyoim.
If you want to use the internet for bad its available but FB makes it easy,makes it look like its OK,FB is like going into a mixed gym Vchulu , and its up and personal.More important than forbidding the internet, the Rabanim should focus in on the individual most problematic web site for the regular average person. FB is the Machla of this generation we have to eradicate it. My personal issue is I deactivated my account but I know that if I log back in everything will be there as it was there before. I wish there was a way to deactivate it and loosing all the information there that would be real step in the right direction.