You need the other users password to do that, or be root, so it is not a problem. Also, in our system, non admin users don't have linux shell access anyway, the

You need the other users password to do that, or be root, so it is not a problem. Also, in our system, non admin users don't have linux shell access anyway, they get a custom shell that uses the rest server as the backend. The admin user can get linux shell and run commands as other users or do whatever they want but that is expected.