We just had one of those airspace violations in DC, resulting in breathless cable news coverage and brief lockdowns at the White House and Capitol. I happened to be listening to my police scanner at the time, so I could hear how quickly the F-15s from the combat air patrol responded to the little Piper Cub that wandered away off its route. The fighter jets were there within about three minutes of the first alert. Pretty heartening.
Also on the positive side of the ledger: the Department of Defense and Department of Homeland Security talked to each other, and quickly. Encrypted radio frequencies buzzed in their secure glory. Reagan National Airport is smack dab in the middle of the capital zone, and about a dozen jets were instantly re-routed until the emergency was over.
Less desultory: eight and a half years after 9/11, nearly all of the United States Capitol Police still uses analog, unencrypted radios to communicate. As a scanner hobbyist and journalist, I'm cool with that. As someone who often works at the Capitol, I'm a little worried. The recently-passed stimulus package reportedly contains money for the USCP to upgrade their radios, so perhaps this security hole will be plugged.
I'm not revealing any secrets here... anyone with a scanner and a computer can find the USCP frequencies and start to listen.