X-Ray body scanners have been controversial since the Transportation Security Administration began installing them in airports after the failed underwear bombing on Christmas Day, 2009. Now, the TSA is planning some changes that travelers -- and taxpayers -- will want to know about. Nearly half the scanners are going to be moved from America's biggest airports to smaller ones. But 90 others — worth $150,000 each -- will be left sitting in a Texas warehouse. Michael Grabell is a reporter for ProPublica.