Is this true? I hadn't seen this. I've found Facebook specifically don't let you access the emails of a user's friends. Quora could easily receive higher access of course, but this still seems like it shouldn't be possible.
But Quora gets your email address and your friend list, and then when your friend joins they get your friend's email address, so they can email you both about each other.
Oh ok, so the issue is that the person who joins last has information published about them that they may not want published. I can kinda see that but it's not something that would bother me personally. An app like Grindr yeah, but not Quora.