When the idea to place full body scanners in airports was initially mentioned, one of the arguments against its installation was the invasion of privacy. To counteract that argument, the government assured that the machines would not have the capability to record or store images. Well, it seems that this assurance was short lived.
The Electronic Privacy Information Center (EPIC) has uncovered information that proves the machines have stored over 2,000 photos from the airport body scans. Read this letter from Transportation Security Administration (TSA) admitting to the storing of images. Additionally, the Department of Homeland Security (DHS) and the US Marshals Service "have been forced to admit publicly that the machines" have these capabilities. However, TSA claims the storing and recording function is disabled when they install the machines.
Besides the retention of body scans, passengers that have gone through the scanning process voice concerns regarding their ability to choose whether to be scanned. Initially, officials stated that the full body scanning would be optional and that a pat-down could be done instead (based on the passengers choice). However, many passengers are not being given the choice. Read some passenger's complaints.