Comment 72 for bug 861171

Closing this bug as the original problem is solved in trusty.

The default logind (the system that performs the shutdown/restart) allows an active session to perform this action. The greeter is an active session so the user can shutdown and reboot from it even when multiple sessions are open.

There are probably other issues here like:
- The greeter doesn't explicitly warn that the other sessions will be closed
- If you lock down these settings the greeter wont be able to shutdown at all
but these are better covered in new bugs if required.