I come down on the side that it shouldn't be so difficult for Facebook to at least spot some of the 4 bots per human. However, even if you assume it is a hard

I come down on the side that it shouldn't be so difficult for Facebook to at least spot some of the 4 bots per human. However, even if you assume it is a hard problem - thats more reason that they should have listened (and responded!!) when a company identified this problem with some hard data to back it up.