Facebook is trying to make the word “private” meaningless.

“But what his presentation elided was the fact that Facebook does not need to see the content of what people are saying in order to advertise to them. The metadata — who, or what (as in a business), you’re talking to, and even where you are or what time the conversation is taking place as it comes together with other pieces of information — provides more than enough information to make a very educated guess about what you’re interested in, to the point that knowing specifically what you are saying adds almost nothing.”