TSA is expanding a controversial facial recognition program in airports around the US, raising concerns among travelers and lawmakers alike.

According to CBS News, the agency is expanding the program in some 25 airports around the country, using facial recognition to match travelers to their passports. The agency touts the improved accuracy and speed the process delivers.

“We view this as better for security, much more efficient, because the image capture is fast and you’ll save several seconds, if not a minute,” said TSA Administrator David Pekoske.

“Facial recognition, first and foremost, is much, much more accurate,” Pekoske added. “And we’ve tested this extensively. So we know that it brings the accuracy level close to 100% from mid-80% with just a human looking at a facial match.”

Not everyone is convinced, however, with a group of senators sending a letter demanding the program be halted.

“You don’t have to compromise people’s biometric security in order to provide physical security at airports,” said Sen. Ed Markey.

At this time, participation is still voluntary, with travelers able to opt-out. Only time will tell if that remains the case.