You may find that your user account has permission to read the employee salary database. However, you may not be authorized to read that database by corporate policy because you are not a manager. Perusing that database will still get you in trouble, because you aren't authorized to do so, even though your account had the technical permissions to access it.
You may find that you have permissions to screenshot internal databases and post them on facebook, however since you are not authorized to do so by policy, you will be fired.
Etc.