The Trump administration plans to increase the presence of facial recognition technology in the 20 largest U.S airports. A recent directive includes the goal of adding biometric technology to scan almost all international travelers at those airports by 2021, including U.S. citizens.

Now, the U.S. Customs and Border Protection agency will add facial recognition technology to identify 100 million travelers each year — amounting to 16,300 international flights weekly.

Critics say federal agencies are rushing to implement the directive, and may take shortcuts to get there. CBP has no formal limits on the data collection and how it can be used, for example. The agency also did not place the proposed expansion rules out for public review before implementation, as the law requires.

“I think it’s important to note what the use of facial recognition [in airports] means for American citizens,” said Jeramie Scott, director, EPIC’s Domestic Surveillance Project. “It means the government, without consulting the public, a requirement by Congress, or consent from any individual, is using facial recognition to create a digital ID of millions of Americans.”

CBP stated the technology will add convenience that will benefit airline passengers and did not agree there were privacy issues about how the data will be used.

Airlines have been testing biometric initiatives, including Delta Air Lines, American Airlines and British Airways.