The level of analysis goes so deep that it's mind boggling. Just from a few "likes" they can perfectly analyze your personality. There is a company who does that. Illuminus. I checked it out for myself. Even though I don't interact on facebook anymore, I am classified as a "high risk individual" because I am open-minded and extroverted. They claim that after just a few likes they know more about your personality than yourself. They can predict your behavior. The data is already out there and stored safely, deleting them will not make a difference. Check it out! https://illuminus.io/en/