So, a question to developers reading this: would you be happy to work alongside a person who participated in the development of this system?
Not a Facebook employee, but I've wrestled with these questions after years in investment banking and a bit of adtech.
Almost anything that pays well isn't going to the end goal of feeding orphans, or improving society in any way.
The fairer question to ask is if the strategy team pitching such work/product understood the moral implication of the work.