If you want to see what an infectious virus FB really is- I gave an iPad to a mostly-technically illiterate adult (a 60's year old friend) soon after her moving to a new address) and when I came back in 6 months and saw how many things she signed up to, signed in to, shared, and became a part of without even realizing it. I had one letter of her last name typo'd on the FB account and within 3 months this version of her last name was in public records, her annual income (very accurate) and a shocking bit more of her personal/professional history, not to mention all her online games and accounts were linked through the FB account, something she didn't even realize she did (by FB's design, of course).
The ONLY reason Apple lets FB have apps on their phones is to prevent all those FB users from switching to Android phones, otherwise they would treat it like the infectious disease it is.
Remember- if you take a nude selfie in your bathroom mirror with a phone with the FB app on it, they LEGALLY have the right to access that photo (just because it's on your phone- even if you never put it in their app/system) and the right to view, keep, review, and attach it to your identity. Forever. On a system that knows all your family, friends, ex's... and to keep it even after you close your account and delete your app. Read the TOS. While it's unlikely they'd USE that, imagine what else they do/save/use that is in some way profitable to them.
The guy started the company by stealing the idea, and his business model has been to steal whatever he could get away with ever since.