I just spent three months hiring in NYC, and now that I think about it, I haven't seen a single person mention they were considering counteroffers from Facebook. For context, Facebook and Google are the two largest tech companies with a significant NYC presence. It's telling that a substantial portion of our candidates admitted to considering competing offers from Google, but literally no one was considering Facebook…
Nope. People who I know have turned down FB offer was purely because they see them as less stable company and have doubts if their stock will keep falling. No one wants to wake up a month later to find out that their signing bonus just got reduced by 10% due to bad news cycle. I would estimate that less than 10% of people turn down employer due to privacy related ethics. Also, on side note, FB has jacked up stock bonuses for existing employees. Their attrition rate is virtually unaffected despite of all the bad news.