fun
Although, what they know of you depends on what you do, so you are stuffed if you reveal lots of genuine details of your life /opinions / interests on FaceBook, Twitter etc.
But if you do not (or consistently cultivate an online persona that is very unlike the real you) then you put a spanner in the works.
.. maybe do the same trick as with loyalty cards (keep swapping them between friends so that lots of people use them and so products purchased make no sense (if you pick a decent demographic of people to shuffle between obv)) and have rotating guest authors on your Twitter, FaceBook (obv that needs you to not care in the slightest about what gets posted on them!)
Biting the hand that feeds IT
