If you use Facebook, this article is a must-read. It’s now common knowledge Facebook is always watching and analyzing how you use the service. But the breadth and depth of the company’s participation in the data brokering economy is staggering. The worst part? You literally signed up for it.

Facebook obviously doesn’t charge its users money, but the mere act of creating a profile affirmatively grants the company total access and usage rights over everything you do on the site. It even shares its data about you with data brokerage firms whose business model is monetizing you.

This is all stuff I have personally known and accepted for a long time, but as the ability to easily aggregate dossiers on anyone and everyone increases, it’s more important than ever to educate yourself and those you care about. Facebook is not free, and in fact it’s worth asking whether the price most people pay by clicking a harmless-looking “I agree” button is really worth it.