This is good information to share around your organization, to either take advantage of, or to avoid accidentally misusing. New sharing settings in Google Docs:
Private: Private docs are accessible only to people or groups you’ve explicitly invited to the file. Anyone trying to access the file will have to sign in to verify that they have access to the file.
People at your organization with the link: Docs set to this option are accessible to anyone inside the domain who knows the URL of the file. If you also select the ‘Allow anyone to edit’ option, anyone with the URL will be able to view and edit your file. This option allows you to easily copy and paste the file’s link into chat, email and calendar invites.
People at your organization can find and access: Docs set to this option will be indexed by Google Docs search and may be opened by anyone in your organization.
If your Google Apps administrator allows sharing outside of your organization, you will also be able to make a file Public on the web or available to Anyone with the link (no sign in required). Administrators can also control the default visibility setting from the control panel.