By the way, to address the problem of guessing your friends' identity: I know this is a critical point in the system and thus I added something to prevent that

By the way, to address the problem of guessing your friends' identity: I know this is a critical point in the system and thus I added something to prevent that guessing, of course. However, it's a dirty fix, as it may introduce new issues (but of course that may be improved soon): When address books are synced with the friend lists in the app, those "friend" connections are always reciprocal. So even if you have only one single person in your address book, and you're seeing posts from friends in the app, you don't know if that's the person in your address book or any of your friends who has started using the app as well. Someone that you don't want to hear from may add your phone number to their contacts, but you may block any user inside of the app and this blocking is persistent.