Department of Defense Warning in Login window

I found this weird thing while going through the Core Services folder. The file I am talking about is located in System> Library> Core Services> Security Agent Plugins> SCLoginPlugin.bundle> Contents> Resources> English.lproj

The file is called login.nib. If you have interface builder and you open it up, it contains the login window, plus another window which I have never seen before. The title of this window is "Notice" and all it contains is an image(which is not displayed but titled "bang"), an "OK" button, and a text area. The text area contains a Department of Defense warning including this and more:

"This computer system, including all related equipment, networks and network devices (specifically including Internet access), are provided only for authorized U.S. Government use."

Click to expand...

I searched for this warning in Google and it is an actual Department of Defense warning.

I'm not sure what this window is or why this warning is in there.

Also the contents folder of SCLoginPlugins.bundle contains army, marine, and navy seals and all sorts of other logos, including sample identification icons. It also contains DoDAnchors-Deployment file. DoD stands for Department of Defense. I have never seen these before. What are they doing in there?

What do you guys think?