How can a security administrator of Google Apps for an organization that has linked @organization.com accounts to Google Apps to know and disallow that users use their users@organization.com accounts to register and login to third party apps like for example Security Stackexchange?
The risk is that when a user access an app, a forum or a webapp, using Oauth authentication against Google, the user gives privileges to the authenticated application. For example, reading your Google Drive documents.
I know that you can use Google API or CASB (Cloud Access Security Brokers) applications (expensive) in order to control it but I'm looking other possibilities.
