The point of the article is you should be even more paranoid about what Facebook has without your microphone. With the amount of data that's floating out there

The point of the article is you should be even more paranoid about what Facebook has without your microphone. With the amount of data that's floating out there about you and your friends, these coincidences are way, way more likely, and are very reasonable if you think about it. Your friend told you about some restaurant, and then an ad shows up on Facebook. Why is your friend telling you about it? Maybe he went there recently enough? Maybe he gave the restaurant a review? Maybe the restaurant has a list of people who've been to the restaurant before and is using Facebook ad manager to target those people and their friends? It's on his mind, so maybe that's causing him to leave enough breadcrumbs behind to make Facebook have an inkling of his interest, and you're his friend so Facebook knows to perhaps nudge you as well. And maybe Facebook actually has some idea that you and that person are meeting (yay geotracking!) Now add a prediction system driven by deep learning models that are terrifyingly good at finding signal with a decent dose of probability (think of all the conversations you've had that didn't result in eery advertising), and you've got yourself a frightening reality where a company doesn't need your thoughts to make a decent guess about what you're thinking. Frankly it might not even be this complicated. Maybe your network searching for or purchasing things is enough for Facebook to guess you're a decent candidate for the ad too, and you guys just happen to meet up on the same day.