Tim Berners-Lee

To ask questions can become the laziest and wobbliest occupation of a mind, but when you must yourself answer the problem that you have posed, you will meditate your question with care and frame it with precision.

Every time you log in to Facebook, every time you click on your News Feed, every time you Like a photo, every time you send anything via Messenger, you add another data point to the galaxy they already have regarding you and your behavior.