Was Facebook's Research Ever Really Ethical?

It's not a question of whether it publishes its results or not—it has to do research to evolve for its users—it's question of whether what it's doing is ethical in the first place.

Because, as Randall Munroe muses in the mouse over of today's XKCD ,"it's not like we could just demand to see the code that's governing our lives. What right do we have to poke around in Facebook's private affairs like that?" [XKCD]