Correct reasons for opting out of millimetre wave scanners

I tried the radiation argument the first time, just after they were introduced, but this argument doesn't seem to be too valid now since the millimetre wave scanners aren't very powerful.

Who told you this? The guys at the gate who don't want to pat you down? Tell them you only take medical advice from certified doctors and PhD's.

You don't need to give any excuse at all. They can't force you undergo this procedure, you volunteer to it. If you don't want to - then you don't. They'll have to use the good old manual search on you.

That said - why do you care? Do you believe that it will cause you any damage? I'm pretty sure we're all exposed to much higher levels of radiation from our cell phones, microwave ovens DECT phones and WiFi routers, so once in several months that you need to go through this scanner (and its not always used in SFO) won't add much to that.

If its privacy concerns... Well, feel better when someone standing right in front of you touches your groin? I don't.

What is it?

The only reasonable (to me) explanation would be ideological: you don't want it because you believe they shouldn't do it altogether. Well - you can just say so, its your right.

Well, you can still try the privacy argument, among others. Here's a summarised version of what Wikipedia has to say:

Privacy advocates are concerned about the use of active millimeter wave technology because it effectively implements routine and, in many cases, mandatory virtual strip searches. It allows screeners to see the surface of the skin under clothing, prosthetics including breast prostheses, and other medical equipment normally hidden, such as colostomy bags.

Tumors - While the majority of animal cancer studies show no response to chronic exposure of microwave radiation, some show an increased rate of tumor growth. The same increase also occurs in chronically–stressed animals not exposed to radiation.

I've also seen some people claim that they get claustrophobic being in the machine, but that's a tough argument to 'prove'.

Not only is the "radiation" issue invalid, but the privacy issue is also a non-issue. After the public's dislike of the remote viewing of images, the scanners were changed so that instead of producing an image that someone looks at and then radios the screening person where to check the passenger, it now automatically finds objects itself and uses a generic, cartoon-like avatar of a person as a map, and displays a yellow box on the area of the passenger that the screening person should check. This eliminates the need for any image. It is also good for the screeners, since it lessens the manpower needed to run the operation. The only (small) downside is that since the computer can't think like a human, you will get more false positives that would otherwise be dismissed by a thinking person looking at an image and recognizing a harmless object like a nickel or something.