The Defense Advanced Research Projects Agency, based in the US, has completed a proof of concept using the Oculus Rift in cyber warfare -- both defensive, and offensive.
In keeping with the unnecessary B-grade sci-fi theme, the setup is called Plan X. With two motion-sensing Razer Hydras, users are able to navigate through computer networks represented as spheres. In the demo below, a user would protect networks from a hacker wielding the dreaded DDOS attack.
It's unclear exactly how representing data in 3D makes anything quicker or easier, as opposed to just looking at several monitors. In a Wired story, Program Manager Frank Pound talks about "immersion" and "swimming in data", but not a lot about practicality.
They might not be willing to share the how they're getting from Point A to Point B, but they're pretty clear about what Point B is. The endgame is not only the ability to defend networks, but also attack networks -- the example given is one in which a hacker turns a facility's lights out to give soldiers on the ground a tactical advantage.
The agency also acknowledges the Rift might well be a completely different product by the time Plan X is actually used, sometime around 2017. But DARPA seems to be in the loop on future plans for the Rift -- meaning John Carmack is indirectly working for not only Facebook, but the military. Times have changed.