 a globally rolled out feature over the next several weeks called link history. They pitch it as a feature that keeps a list of all the links you click within Facebook's mobile app. So you can review them and find links that you might want to revisit later. This is an opt out feature, but Facebook will show you a pop up notifying you that the feature is active at which point you can then opt out of it. I look at this and I think if I don't know whether they should have it or not, I would say no, but it's not the end of the world if they have a little link history on you. As long as you know you're giving it to them, you might get better ads because of it and you get the benefit of being able to go back into your link history in an app that you wouldn't otherwise be able to go into. So I don't think this is the end of the world if you say yes to it. It's actually the way it's supposed to work. You know you're doing it and what you're getting for it.