On a related note, FB seems to use the microphone, with permissions disabled, when the app isn’t even open, to listen in on our conversations and later advertise things it hears us talking about. I don’t have 100% proof of this but we’ve mentioned things we never googled or even put in our phones or computers and they are pretty specific (purple dress, tactile diaper bags, beer) and they come up the next day or two in a FB ad or recommended post.

EDIT: I get that the "general consensus" is that this has been debunked, and that it's just coincidental. But we have had several situations where there's no other reasonable explanation. Like how our friend, who has never drank beer and never drinks any kind of alcohol, came over to our house, and we discussed beers, and within a few hours she got some beer ads on FB. This kind of highly specific thing has happened too many times for any other explanation to make sense.