[scottmp10]

It isn't an oversight by Facebook - it is by design. Facebook was a part of the decision to use Facebook login credentials to log into Spotify. Additionally, Facebook does not list access to your friend list (and your friend's email addresses) in their list of permissions. Rather, those details are implicit in using Facebook to authenticate.

As an example, using FB to authenticate with Quora does not list access to friends list in the permissions but Quora will send an email to every friend of yours already on Quora to notify them that you joined.

Another issue with this is that if you have never given any Facebook permission to Blizzard, but happen to use the same email address as listed on your Facebook account then Blizzard will attach your real name to your account without your permission.

[intelekshual]

Facebook does not give implicit permission to access "your friends' email addresses." In fact, they don't grant that permission under any circumstance.

[nitrogen]

What I believe the OP was saying is that they grant access to the friends list, and that Quora already has many of their e-mail addresses. Thus, they indirectly get access to your friends' e-mail addresses.

[analog]

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.

[fennecfoxen]

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.

[analog]

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.