On my own last night and bored enough to actually do it – download my fb profile and have a look.
I`m my no means living behind the moon, but what I found deeply shocked me – they have ALL my friends` mobile numbers (even those who are not on facebook – probably pulled from WhatsApp? I know some would FREAK OUT if I told them!!), tailor my adverts to what I like on Instagram, and they list *everyone* I ever was friends with, including exact dates when I un-friended them (but not people who unfriended me). And a long, long list of photos I deleted YEARS ago. And all my pn`s including pictures which I sent through those.
And the only way to get at least *part* of that information off their server is to delete my account altogether and start a new one. And freak out again in a couple of years. But I`m seriously contemplating it..