Military it's own Big Brother?

CNN recently posted an article describing The U.S. Military's newest project to increase internal security measures. The purpose of the $35 million project is to research ways to scan billions of internal emails to identify military personnel who may potentially commit crimes of terrorism. The goal of the project, conducted by the Defense Advanced Research Projects Agency (DARPA), is to identify potential criminal behavior in advance so that crimes can be prevented before they are committed. DARPA, which is credited to producing the internet, GPS, and stealth technology, is currently working to produce the technology necessary to compile such a large amount of data into usable information.

What do you think? Is this an invasion of privacy or a smart way to strengthen Homeland Security?