KnpLabs/KnpOAuthBundle — comment on commit c8dd21f33787386402e699268f658f6f452c31d7
File: Security/Core/User/OAuthUserProvider.php line 17
By stof:

you should check if the user is an OAuthUser and throw an UnsupportedUserException otherwise.

And this provider can be a security issue as it allows using any username