I am reminded that the "The Dunning-Kruger effect" continues to demonstrate the stupidity of the human race. And those guys at Facebook stumbled upon this social behavior, that is utterly a waste of time, but generates a lot of cash for themselves. Granted, there are the marketing aspects of said social medium, or utilizing the Facebook "cattle" to generate your own money for yourselves. But seriously, this is what the human race has become?
Is this worse than the water cooler? A harmless diversion of some productivity? Perhaps, but more likely not, especially if the suggested statistics of 7 hours per day for the average Facebook user is correct. But as the DK Effect research suggests, the only way to really to change the behavior is education, where the user finally sees for themselves that what they are doing is not the best use of their time. Simply "knocking heads" isn't the answer, nor is anything legal (although I'm all for dealing with the privacy issue at Facebook, since their behavior is certainly questionable).
Time will tell, and certainly there is history to write here yet.