Yesterday I posted a small piece (Re: e-mail spying could have stopped London Bombers) about suggested moves by British authorities to leverage the bombings to further their agenda (namely: more spying on the citizens). Along the way I noted an article discussing QinetiQ and a proposal to install their scanners in the Tube stations in London.
Today The Register has published a lengthy analysis of the possible success of that idea:
Could the 'see through clothes' scanner stop London terror bombs? (By John Lettice, TheRegister.CO.UK, Published Monday 11th July 2005 11:44 GMT) Their prior coverage of QinetiQ is here.
The analysis goes like so: forget the tittilation for a moment that the scanner shows peoples naked bodies. Instead look at the practicality and whether the company has truly demonstrated the necessary features.
The typical entryway at a mass transit terminal is wide, allowing several people to enter/exit at once. This is for convenience of the mass transit users. Think of the stereotypical shot of Grand Central Station (NYC) and the thousands of people in that room at any one time. Further, typical mass transit stations in heavily populated areas have multiple entry/exit doors.
This presents a problem - The more people passing through the portal, the more the scanner has to sift through and detect. Say you've got 60 people entering the door each minute (not unreasonable for a busy mass transit station in a large city). You've got one second per person to scan them and recognize any naughty bits like guns or bombs. That's not a job for a human, as evidenced by the slowness of scanning people at airports.
The scanning system at airports also demonstrates the problem with using a scanner at a mass transit terminal. These work best when you scan one person at a time. This means forcing people into an orderly line. It's already painful enough to do that at an airport, but can you imagine what it would be like at a mass transit terminal to do so?
Also, experience in Israel has apparently shown that the bombing target then becomes the line, rather than trying to sneak bombs through the scanner to detonate them inside.
The Register's analysis is pretty thorough and interesting.