This fellow attempted to board a plane with an IED ("improvised electronic device") and was turned away by the TSA.
Yesterday I flew out of Rapid City, SD as part of some work I'm doing. I was in the security line when I heard my name paged.
This crack security staff was digging through my bag. They were concerned because I brought a microcontroller programmer. Actually, it wasn't just the programmer, it was the 1 ohm resistor I had spliced in series with the power lead to measure current, and the 10 second RC filter I had placed across that to give my DMM a better chance of reading the average current.
"Sir, this is an improvised electronic device. You will never be allowed to fly with this."
I responded to many questions with information about my occupation, circuit theory up to and including Ohm's law, and a discussion of the market for bicycle power meters. But they still would not let me fly with the programmer. I had to leave it behind.
I was finally able to fly out ten hours later, with a brand-new-in-the-box MSP430 programmer. Apparently, it's not "improvised" if it comes in a printed box.