I don't think they 'll manage to convince anyone that maximum profit can be a legitimate reason - at least not in the current climate. They can claim however that, since facebook's business is selling targeted ads (which is truly their source of revenue), their system simply needs user's data to work.

I believe that facebook DID ask about permission with its terms pop-up that i saw on the web. In any case however, any complaint against facebook will be judged emotionally at this time, so the details may matter less.