Nothing is free and the price you pay for using many popular web services is letting them track your internet activity.
So if that makes you slightly uncomfortable here you go…
I protect myself from Facebook tracking me by using a Fluid browser for Facebook. Because I paid the US$5 to register the app, I can use separate cookies from Safari.
For more detailed instructions on how to fight the law go here.
Or you can do like me and delete your time sucking Facebook account.