I don't think it's necessarily a contradiction. You either have to run your own server, or you have to trust someone else at which point you might as well just

I don't think it's necessarily a contradiction. You either have to run your own server, or you have to trust someone else at which point you might as well just use Facebook. The entire point of Disaspora is that you don't have to trust anyone. Once you have some random, unknown person hosting it for you, you're just using Facebook but with fewer people.