Finally, Bruce Schneier wrote a sensible CNN article about the Facebook/Cambridge Analytica scandal: It's not just Facebook. Thousands of companies are spying on you.
Don't be under the misapprehension that this was a mistake or a one-time occurence. It's precisely the business that Facebook/Google/Twitter and the like run. Those companies make a living selling your data for the exact purpose of targeting you. It's pretty much the definition of personalized advertising.