The Transportation Security Administration is letting airplane passengers formally critique its $2 billion body scanning program -- a requirement for substantial federal programs that TSA had skirted for about four years.

The concession follows a 2011 court order siding with the Electronic Privacy Information Center in part of a lawsuit. The privacy group argued TSA must release undisclosed rules for the use of so-called advanced imaging technology and allow citizens to comment on those rules.

"We will review and analyze all comments once they have been collected," TSA spokesman David Castelveter said Sunday night. He stopped short of saying whether the agency will consider changing the program rolled out nationwide in 2009 in response to submissions.

Agency officials acknowledge in the public notice to be released on Tuesday that "the U.S. Court of Appeals directed TSA to conduct notice-and-comment rulemaking on the use of AIT as a screening method for passengers." Passengers will have three months to file opinions.

Reacting to TSA’s move, EPIC President Marc Rotenberg said, "The TSA unlawfully deployed body scanners at airports in the United States. Now the public will finally have the opportunity to express their views on TSA airport screening procedures.”

The court did not order TSA to halt current operations, stating that "vacating the present rule would severely disrupt an essential security operation" and that the regulations are "otherwise lawful."

The agency has spent $841.2 million on the program since 2008 and expects to spend roughly $1.3 billion more through 2015, according to the notice.

In recent months, TSA has begun responding to other citizen complaints and new congressional mandates involving body scans. By May 31, as required by a 2012 law, the agency plans to unplug machines incapable of displaying only a generic body image that masks passengers’ actual physique.

TSA also is spending $245 million on new, smaller systems expected to expedite lines and better detect explosives. In addition, TSA in December agreed to an independent study by the National Academy of Sciences on cancer risks from body scan radiation.

TSA ramped up installation of the machines after an al-Qaeda affiliated terrorist unsuccessfully tried to ignite explosives hidden in his underwear aboard a Detroit-bound airplane on Christmas Day 2009. Last year, individuals from the terrorist’s sect developed new incendiaries designed to overcome the underwear bomb's inadequacies.

On Sunday, Castelveter said TSA will evaluate all comments on the use of the technology, including remarks on privacy, safety, efficiency and cost ramifications. However, he noted the agency has addressed many of these implications.

System upgrades now protect privacy "by eliminating passenger-specific images," Castelveter said.

In addition, "the safety of AIT units currently deployed at airports has been tested by TSA and independent entities and all results confirm" that the machines “are safe," he said.

The systems remaining after June 1 "do not emit ionizing radiation, and thus do not pose any radiation risk to passengers, airline crew members, airport employees and TSA employees," Castelveter added.