Great resume Larry Kim but for me it left an eleven points and it is huge ^^ To be accurate, as much as possible, you MUST BE CONNECTED ON FACEBOOK to use the search engine! For me it can be an issue of a long term. Anyway you don’t need to have a google account, to use Google.com (without Google Personalized Search). The results are still accurate, fast and good enough for many users (like me anyway) .
Finally, I will add one last point (because we know each other so well), that the biggest issue of Facebook (more than Google I guess) is it has to face off about “Filter bubbles” issue that can put any result in a way that lack objectivity and give us a result that the system decide to let us see.