Simple, don't use Facebook. Can't live without Facebook, use an older PC dedicated to searching porn, Google, Twitter, Facebook etc. or you can try these suggestions.
Some of this comes with the territory of using Facebook: If you want to take advantage of its features, then you have to give up a certain amount of information about yourself. But Facebook has ways of keeping tabs on people who aren't even signed up for the service. Fortunately, there are numerous ways to limit the volume of data that it logs.