Looking on the bright side, if FB were given a very broad patent on this, it would mean that we could focus on just blocking FB's efforts and let their lawyers

Looking on the bright side, if FB were given a very broad patent on this, it would mean that we could focus on just blocking FB's efforts and let their lawyers keep anyone else from doing it to us. This is just another step in the privacy versus marketing arms race that started with simple things like cookies and web bugs. Those who care will block it and those who don't will become resellable data.