Facebook is an enabler for individuals to successfully undermine our democratic mechanisms. It shouldn't feel nice to work for a company that has to explain itself in front of the government. The employees of Facebook should be aware of what monster they are building.
I’ve seen this us-against-them mentality play out elsewhere in various toxic cult-like organizational cultures. The NSA was a great public example of just how manifestly horrifying things can get with tens to hundreds of decent people willfully participating in corrupt or unethical practices.
The way this all works is terribly fascinating, but the short of it is that you have to become closed off and indoctrinated in order to fit in. Particularly at places like Facebook, Google, and generally anywhere else that provides free on-campus dinners (a good heuristic), employees build their social circles and identities around the company. This, coupled with various other factors, permits an astounding cognitive dissonance amongst a large group of otherwise benign and rational people.
EDIT There’s an interesting additional complication I’ve seen at times: internal spin. The media gets things about companies so wrong so frequently that it’s almost too easy to discount the things with an uncomfortable shred of truth as ‘fake news’.