Apparently a redditor, marvellously named Gynoceros, was travelling through Newark airport when the TSA confiscated his Giottos Rocket air puffer. This device is popular among photographers for its ability to gently blow away dust from delicate camera and lens parts. However, it apparently bears too strong a resemblance to a cartoon bomb to make it past security.
According to Gynocerous:
FYI -- If you attempt to fly with a Giottos Rocket Blower (you know, rubber bulb you squeeze to force air down a nozzle to blow dust off your sensor -- no metal, no moving parts), the TSA may confiscate it because it "looks like a bomb", no questions asked.
Just f**king happened to me in Newark. I knew I'd get robbed in Newark one day.
At this rate, pencils soon won't be allowed on-board because they could potentially be used to depict a bomb, which is obviously a clear and present danger to the security of these United States. [Reddit via Petapixel]