Ask HN: Anyone worked on Darpa software projects?

Hi, In the wake of the Snowden revelations we all learned the state of eavesdropping software in government. So I'm wondering what else there might be that's over-the-top type of unbelievable software the government might have. While speculation along these lines might be entertaining, I'm more interested in hearing from those who've been a part of such things, so if you can legally talk about it, please let us all know if you've been part of that sort of stuff.