airport in Ghana and four in Nigeria". This has caused some to question how far the U.S. government intends to go with the technology. Unions for airline pilots working for American Airlines and US Airways have urged pilots to avoid the full body scanners. Child scanning There is controversy over full-body scanners in some countries because the machines create images of virtual strip searches on persons under the age of 18 which may violate child pornography laws. In the UK, the scanners may be breaking the Protection of Children Act of 1978 by creating images or pseudo-images of nude children. Parents have complained that their young children are being virtually strip searched, sometimes without their parents present. Ineffectiveness Backscatter and millimeter Some critics suggest that full-body scanner technology is ineffective for multiple reasons, including that they can easily be bypassed and a study published in the November 2010 edition of the Journal of Transportation Security suggested terrorists might fool the Rapiscan machines and others like it employing the X-ray "backscatter" technique. A terrorist, the report found, could tape a thin film of explosives of about 15–20 centimeters in diameter to the stomach and walk through the machine undetected. Terrorists have already evolved their tactics with the use of surgically implanted bombs or bombs hidden in body cavities. In March 2012, scientist and blogger Jonathan Corbett demonstrated the ineffectiveness of the machines by publishing a viral video showing how he was able to get a metal box through backscatter X-ray and millimeter wave scanners in two US airports. In April 2012, Corbett released a second video interviewing a TSA screener, who described firearms and simulated explosives passing through the scanners during internal testing and training. In another test of the full-body scanners, the machines failed to detect bomb parts hidden around a person's body. And in a different test in 2011, an undercover TSA agent was able to carry a handgun through full body scanners multiple times without the weapon being detected. However, in this case, the TSA agent who was in charge of viewing the scanned images was simply not paying attention. Furthermore, an Israeli airport security expert, Rafi Sela, who helped design security at Ben Gurion International Airport, has said: "I don't know why everybody is running to buy these expensive and useless machines. I can overcome the body scanners with enough explosives to bring down a Boeing 747...