It's official.

The military's new Cyber Command, responsible for shielding 15,000 military computer networks from intruders, has become fully operational.

That's the word from the Defense Department on efforts to protect national security information and intercept foreign communications.

More than 100 foreign intelligence organizations are trying to break into U.S. networks, Deputy Defense Secretary William Lynn wrote in the September/October issue of the journal Foreign Affairs. Some already have the capacity to disrupt U.S. information infrastructure, he said.

So the DOD is fighting back.

The cyber-fighting unit, based at Fort Meade, Md., is part of the Offutt Air Force, Neb.-based Strategic Command, the organization responsible for U.S. nuclear and space operations as well as information warfare and global military intelligence.

That's high-tech stuff.