This doesn't work until a large enough number of people do it. Firefox users are about 25% now and that includes most of those who have a clue about computers. There are millions who can hardly tell a keyboard from a kumquat, and studies show a subset of them account for most ad clicks.
It will take legislation to stop this sort of thing. The best approach is educating people - naive users being offended by the "creepy" factor of ISPs monitoring and selling user data is the biggest weapon against this.
