http://www.theregister.co.uk/2005/07/11/qinetiq_tfl_scanner/
John Lettice
"Millimetre wave is currently used by UK immigration authorities as a people detector in order to track illegal immigrants concealed in lorries. Last year the Metropolitan Police also announced that it would be getting one, so it it doesn't have the kit already it will probably have it soon. The Met's scanner will we expect be as useless for the organisation as its existing low-dose x-ray scanner, which a while back we concluded had no clear purpose beyond psyops, and which the Met hopefully keeps offering to schools as a weapons detector. Millimetre wave might however be more useful at airports than x-ray, which is currently being tested at Heathrow, and the Times report points to a couple of other areas QinetiQ probably has in mind."