Okay. Here's a serious answer. If the DoD/NASA/FAA/DHS haven't convened classified panels to look at this issue, I'd be amazed.
If I had a good idea, believe me, I wouldn't be blathering it around here.
If someone is in a position to know what's been done, they're not in a position to talk about it.
Now, the amazing thing is that no one had thought the scenario through before 9/11, but they hadn't. If the government hasn't thought it through by now and taken steps to address the issue, we're in deep trouble.
If you think you've got a great idea, maybe you can get someone at DARPA or DHS to give you a hearing.
RM