If you use Facebook, you're going to get an email asking you to accept new T&Cs. This is a chance to not only help yourself, but I think it might help save the world.When you click through, FB make it obscure to actually change the status quo. Your opportunity to deny them personal data they use to categorize what information they serve to you is hidden behind some "Manage Settings" buttons, and a few pages giving examples of how nice it'll be to enable sharing of your religious views, your partner-gender preference, your political inclination, whether to make ads more "relevant" (read targeted) to you, and whether to give FB the right to recognize your face in photos.My recommendation is to say "no" to all of these. And it's not just because I think that's what most people want. There is some preliminary work that a student of mine is leading, which I can't discuss yet in detail, as it is unpublished, but the implications of one of the results is that the best way to fight against echo chambers and the (sometimes hateful) polarization of people online is to have more diverse information shared with everyone.One way to contribute to making that happen is to prevent algorithms from serving you and others a programmatic palette of information. That causes a networked effect of dividing what people see about the world, and thus how they see the world. This is something that I believe we need to work against.And the research seems to show that the most effective way to do that is to share more diverse information more broadly. Enabling FB to categorize and target you and others would seem to have the opposite effect, according to the mathematical models we're looking at.So make the world a better place today: take the time and effort to overcome FB's hiding of your options, and deny them all of your personal information that you can, via those options.It won't save all the problems of profit driven social media companies, but it's what we're able to do now.