Does this help?
How to deprovision devices from my Xfinity Tv App? I am wanting everybody to be kicked out of my stream account on all devices.
you posted in the streaming website area of the form. can you confirm you are asking about users that use the streaming video under your subscription?
Yes I am wanting all users to be signed out of the stream app with my information
go to xfinity.com and sign in, go to account menu and from there go to the users link. are any users listed there? how did the others get your username/password?