The status page at <a href="https://status.cloud.google.com/" rel="nofollow">https://status.cloud.google.com/</a> has now been updated to include<p>"We are investigating an issue with Authentication services. We will provide more information by 07:30 US/Pacific."
Here is a direct link to the specific incident: <a href="https://status.cloud.google.com/incident/appengine/16003" rel="nofollow">https://status.cloud.google.com/incident/appengine/16003</a>