The government responded angrily Wednesday to a YouTube video allegedly showing a 27-year-old Florida man sneaking a metallic object through two different body scanner devices at American airports.

The Transportation Security Administration, though, refused to directly address whether Jonathan Corbett, of Miami Beach, has discovered a method to beat the machines, which number 600 and are in about 140 U.S. airports. The brief video allegedly shows Corbett, who has sewn a pocket to his side, get through two body scanners with a metallic object in that pocket.

"These machines are safe," Lorie Dankers, a TSA spokeswoman, said in a telephone interview.

In a blog post, the government's response was that, "For obvious security reasons, we can't discuss our technology's detection capability in detail, however TSA conducts extensive testing of all screening technologies in the laboratory and at airports prior to rolling them out to the entire field."

It's not the first time the machines, produced by Rapiscan and L-3 Communications, have come under attack. In a three-part series last year, Wired reported that, indeed, there were suspected security flaws with them. Even the Government Accountability Office – Congress' investigative arm – said the devices might be ineffective. And the Journal of Transportation Security suggested terrorists might fool the Rapiscan machines by taping explosive devices to their stomachs.

Corbett's chief insight is based on sample images released by TSA that show what a traveler's body looks like to screeners when passing through a scanner. The body is imaged directly from the front and rear, and is presented in white or light gray, while the background color in the images is black, Corbett notes. Metal objects also appear as black, which means they show up starkly if they are tucked into a waistband or strapped to the person's chest, where the body serves as a white background to the black metal. But, he theorizes, the metal objects are invisible if they hang off the traveler's side – black metal against the black background.

In the video, Corbett asks: "It can't possibly be that easy to beat the TSA's billion-dollar fleet of nude body scanners, right? The TSA can't be that stupid, can they?"

He answers his own question:

Unfortunately, they can, and they are. To put it to the test, I bought a sewing kit from the dollar store, broke out my eighth-grade home ec skills, and sewed a pocket directly on the side of a shirt. Then I took a random metallic object, in this case a heavy metal carrying case that would easily alarm any of the 'old' metal detectors, and walked through a backscatter X-ray at Fort Lauderdale-Hollywood International Airport. On video, of course. While I'm not about to win any videography awards for my hidden camera footage, you can watch as I walk through the security line with the metal object in my new side pocket. My camera gets placed on the conveyer belt and goes through its own x-ray, and when it comes out, I'm through, and the object never left my pocket. Maybe a fluke? Ok, let’s try again at Cleveland-Hopkins International Airport through one of the TSA’s newest machines: a millimeter wave scanner with automated threat detection built-in. With the metallic object in my side pocket, I enter the security line, my device goes through its own X-ray, I pass through, and exit with the object without any complaints from the TSA.

Corbett, who said he works in "technology," is acting as his own attorney in a federal lawsuit against the TSA. The suit objects to him being forced to enhanced pat downs – if he refuses to go through one of the machines – "that require the touching of his genitalia area by TSA officers."

In a telephone interview, we asked him why we should believe that his claims are authentic. He said Wired should do the same type of live testing.

"You don't believe it," he said. "Try it."