I'm building a web application using Go, and it will be just a bunch of ReST services. I plan to use AngularJS as the front end, and it will make service calls to the Go application.
I plan to deploy to Google App Engine, and use it's user authentication service. Is it possible to then limit a user's session to one at a time, so that a user may not share their login with someone else, and then have that that login logged in multiple times concurrently?