On his way to catch a flight, Sen. Jeff Merkley (D-Ore.) was asked to have his photo taken by a facial recognition machine at airport security.

The Transportation Security Administration has been testing use of facial recognition software to verify travelers’ identification at some airports. Use of the technology is voluntary, the TSA has told the public and Congress.

If you decline, a TSA agent is supposed to verify your identification, as we have done at airport security for years.

When Merkley said no to the face scan at Washington’s Reagan National Airport, he was told it would cause a significant delay, a spokeswoman for the senator said.

There was no delay. The spokeswoman said the senator showed his photo ID to the TSA agent and cleared security.

Is facial recognition technology really voluntary if a United States senator has trouble saying no?

What to know about TSA's facial recognition tech

The TSA is using facial recognition technology for a limited purpose that the agency says is accurate. As flying reaches record highs again this summer, the technology could improve safety and efficiency with fewer risks than controversial uses of facial recognition such as police trying to identify crime suspects from vast numbers of images.