Let me start the story by listing what I had in my carry-on bag:
- A class 3b laser driver and head (capable of blinding a person), which requires a power outlet
- 6 ml of insulin, a handful of needles, a blood glucose meter, and lancets for finger pricking (I'm type 1 diabetic)
- A lot of electronics, including a motherboard (PCB) with an FPGA, several custom PCBs with my own ASICs, and a multimeter
- About 20 or 30 meters of cabling (4m of which was 40 way parallel cabling)
- A laptop with an extended life battery
- A flat-head screwdriver and a torx screwdriver (I think the torx was a T6)
- My keys, which contained an LED light, two hex keys, and a keychain screwdriver similar to this one
- My dumb phone
- A change of clothes (and an extra pair of underwear)
- All the relevant papers for traveling, including e-mail exchanges with the lab where I was going to be working
The guy working at the luggage screener pulled another guy over when my luggage was passing through, and they had me come over to the machine. They needed to re-run my stuff in separate containers --- they said they needed a better view of the electronics. So I unpacked all the stuff, and they ran it in about five separate containers. On the last container, which contained the contents of my pockets, they pulled out my keys, pointed to the keychain screwdriver, and were like, "Um, what is this?" I explained to them that it was a keychain screwdriver, and they said, "We're sorry, tools aren't allowed on the plane. You cannot take this through, but everything else is okay."
Now, at this point, I'd like to give a little history. I received this keychain screwdriver as a present from my sister in December of 2009. It has been through security at airports at least 10 times (6 flights within Europe, and 4 flights to and from the US). I wasn't sure if they maybe misused the word "tool" --- they weren't native English speakers --- but I decided not to push my luck, and told them just to throw it away.
The flight back was the same, with security requiring me to re-run all the electronics, except nothing was confiscated. At neither location did security ask me why I was bringing a laser on a plane.
So, in case you are wondering, it is okay to bring a laser that can blind a person onto a plane, with a power source for at least a few minutes of operation (a laptop battery). You can bring enough insulin to harm a few fully grown people quite seriously, probably killing them. You can bring custom electronics and custom cabling onto a plane. You can even bring fully sized screwdrivers that are for security screws like torx screws (I find it unlikely that planes are going to use Philips or flat head screws). And you can bring all of this in your carry-on. But a keychain screwdriver? Well, my experience suggests there is a 10% chance that this will be confiscated.
I don't want to sound upset at the people at the checkpoint. They were nice to me, and I wasn't acting funny. I'm also a white male, which probably helped by not attracting suspicion. I complied with their requests immediately, and answered any questions they put to me. They had a line of people after me that were probably not happy about the jerk with the electronics having his equipment re-run. In fact, I'm happy with the people at the checkpoint. I needed to run a research experiment whose results are important to cancer detection. It was good for me that a laser, diabetic supplies, and custom electronics cleared the checkpoint.
It bugged me a little that my keychain screwdriver was confiscated but my torx and flathead screwdrivers were not. Did the security guys want to feel like they were doing something? I don't know. But a different question keeps nagging at me --- if I can bring a dangerous laser, deadly amounts of insulin, and custom electronics onto a plane, what purpose does "security" actually serve at airports?