No-one was sneering, just pointing out that we already use many similar things.
By the way, my "tinfoil helmet"link was very informative. It says:-
"the intensity of a Wi-Fi signal is around is 100,000 times less than a microwave oven. The oven is a targeted device that operates at very high voltages and short distances. Wi-Fi routers operate at very low voltages, broadcast in all directions, and are used at relatively long distances.
Since radio waves follow the inverse square law – like light, sound and gravity – then each time you double the distance, you get only a quarter of the energy. In other words, the signal strength falls off very rapidly. At normal operating distances, Wi-Fi's intensity is generally so low that it's not worth worrying about: it's just part of the "smog" that is generated by radio and TV signals, AC mains wiring, the motors in home appliances, and the universe in general. (As my colleague Charles Arthur once pointed out here, the wavelength of Wi-Fi signals is the same as the cosmic background radiation: 12cm. If you're worried, don't go outside.)
.... The electromagnetic spectrum stretches all the way from very long wave radio frequencies to very short wave gamma rays, with visible light somewhere in between. We know that types of ionising radiation with wavelengths shorter than light tend to be dangerous. Examples include ultraviolet (UV) rays, X-rays and gamma rays. (The ultraviolet part of sunlight is certainly dangerous. Wear sunscreen.)
However, the non-ionising wavelengths that are longer than light tend not to be dangerous. These include infra-red rays, microwaves and radio waves. At 2.45GHz, Wi-Fi comes in the microwave band along with baby monitors and mobile phones. After that come the radio frequency bands used for TV broadcasting and AM/FM radio, and further along, long wave radio (famous only for Test Match Special and Economy 7 heating signals).
Of course, it does make sense to minimise risk, as long as you concentrate on the biggest risks, not the trivial ones. If you want to do that, the mobile phone must be the first thing to go. In use, the phone is held close to the brain, while the Wi-Fi router may well be in another room (inverse square law). It has been estimated that you get a bigger dose of microwaves from one 20-minute phone call than from a year's Wi-Fi.
Twenty laptops and two routers is roughly equivalent to one mobile phone.
If you are extremely fussy about Wi-Fi, then make sure you sit 1m (or more) away from the router, and don't use your laptop on your lap. Put it on a table or tray instead. I don't think there is a risk, but you may feel safer if you remove a non-existent risk."
