U.S. airline passengers are growing increasingly frustrated by airport security checks, showing irritation with the widespread use of full-body image detectors and the introduction of more intrusive pat-downs.

Annoying security checks are nothing new. The checks grew more intense after the 2001 terrorist attacks, and then again after the failed attacks of "shoe bomber" Richard Reid.

But the recent introduction of intrusive body pat-downs and full-body scanners have many questioning where security ends and invasion of personal privacy begins.

A week before some of the busiest flying days of the year, irritation with the checks has hit the boiling point, with some passengers refusing to submit to them, and even pilots and crew saying they're sick of it too.

The full-body scans show naked images of the passenger's body, without their face, to a screener who in a different location. Passengers who refuse to submit to those scans undergo a pat-down which involves sliding the hands along the length of the body, along the thighs, groin and breasts.

In the last week, passengers refusing to put up with the pat-downs have become Internet sensations.

One passenger, John Tyner, posted an item to an Internet blog over the weekend to describe how he became ejected from the San Diego airport after refusing a full pat-down of his groin.

He said he told one federal Transportation Safety Administration worker, "If you touch my junk, I'm gonna have you arrested."

Tyner, 31, a California software engineer recorded himself challenging security agents at San Diego International Airport. When he was singled out for a body scan, he refused to go through the full-body scanner.

That meant he had to submit to a pat-down by an agent. The security agent explained to Tyner that he would have to touch his groin area.

"I told the person that being molested should not be a condition of getting on a flight," he told the Associated Press Monday.

"This is not considered a sexual assault," a supervisor can be heard telling him.

"It would be if you were not the government," replies Tyner.

Tyner was eventually told he could not fly at all and was escorted back to the ticketing area, where he got a refund for his ticket.

His refusal has led to online sales of T-shirts and more with the words, "Don't Touch My Junk!"

The cellphone footage of a hysterical three-year-old girl being frisked by a TSA security worker at a Tennessee airport sparked outrage when it was posted on the Internet this week and reported on by several mainstream media outlets.

The footage shows three-year-old Mandy Simon squirming and screaming "Stop touching me!" as a female TSA employee - her face purposely blurred - pats the girl down while in her mother's arms.

Mandy's father, a U.S. TV reporter, filmed the clip in March 2008 but the clip has found new life this week on the Internet.

The head of the Transportation Security Administration, John Pistole, told a Senate committee about his department's policies and procedures earlier this week that he understands the privacy concerns of passengers, but says the government must provide the best possible security for air travellers.

"I'm not going to change those policies," he declared Wednesday.

Responded Sen. George LeMieux, from Florida: "I wouldn't want my wife to be touched in the way that these folks are being touched. I wouldn't want to be touched that way."

Pistole, who became TSA chief in the summer, says he has reviewed reports in which undercover agents were able to slip through airport security because pat-downs were not thorough enough.

He said that given a choice between a planeload of screened passengers and a flight with no lines or security checks, "I think everybody will want to opt for the screening with the assurance that that flight is safe and secure," he told the senators.

An online campaign on Facebook dubbed "National Opt-Out if the Airport Scanners Day" is urging people to take part in a boycott next week, Nov. 24, and refuse to use the full-body scanners, which the page's administrators call "virtual strip search porno-scanners".

Pistole has said such boycotts are "irresponsible."

"On the eve of a major national holiday and less than one year after al Qaeda's failed attack last Christmas Day, it is irresponsible for a group to suggest travelers opt out of the very screening that may prevent an attack using non-metallic explosives," he says. "This technology is not only safe, it's vital to aviation security and a critical measure to thwart potential terrorist attacks."