The problem is that Facebook has way too much power. Have you read up on the offline data collection? Through cookies they can associate your account if you visit a webpage. You would go to a website, say a clothing store, then using a combo of IP, cookies, device info, etc, that website tracks your info and sends it to Facebook. Facebook checks if they have a user that matches those pieces of data. If they do, they will share that with the business. They allow users to opt out of being shown any ads from that business, but they keep all the data!