The message to travelers hoping to avoid invasive security measures this holiday season: your pain is understood, but you have to do it anyway. 

TSA Check Point (Courtesy Creative Commons)

John Pistole, Chief of the Transportation Security Administration, said that he understands the personal nature of pat-downs and how it makes passengers uncomfortable, but called the measures necessary.  

"We're not changing the policies, because of... the risks that have been identified," Pistole said on CNN's "State of the Union." "We know through intelligence that there are determined people, terrorists who are trying to kill not only Americans but innocent people around the world."

The controversy began Nov. 1 when the T.S.A. implemented more aggressive pat-down procedure. Passengers who refused to go through the full-body scanners were subject to the pat-downs. The full-body scanners were another source of contention, as they show an outline of an unclothed body and are seen as graphic.

Despite the criticism, the T.S.A. says a poll shows that 80 percent of the public approves of the measures. 

On Saturday in Lisbon, President Obama acknowledged public complaints but said T.S.A. and counterterrorism advisers had told him “at this point” the measures “are the only ones right now that they consider to be effective against the kind of threat that we saw in the Christmas Day bombing.”

Secretary of State Hilary Rodham Clinton told CBS’ “Face the Nation” on Sunday that she would not like to go through a security pat-down, adding "who would?"

"I mean obviously the vast, vast majority of people getting on these planes are law abiding citizens who are just trying to get from one place to another. But let's not kid ourselves. The terrorists are adaptable," she told NBC’s “Meet the Press.”

For the T.S.A., Pistole said, "it comes down to how do we give the highest level of confidence to everybody on that flight that everybody else has been properly screened, including you and me."

He added that, “The advanced imaging technology is designed to detect non-metallics. So you just have to make sure you take everything out of your pockets. So if there's no alarm, there's no pat-down."