A short while ago, I published a post which discussed the only sure way of disabling GPS in your cell phone: Taking out the battery. Why, I asked, can't we make that task easier by installing an on/off switch?

One reader -- call him B -- sent in his thoughts. The words below the asterisks are his:

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Hi there Joe,

You wrote...

The easy fix: Why don't we ask our representatives to force cell phone manufacturers to provide a switch that turns off the freakin' GPS? (And why don't citizens of other countries ask their governments to do this?)

The GPS should be there only when we want it. Going hiking? Turn it on. Need directions? Turn it on. Meeting your lover or pot dealer? Turn it off.

Of course, I'm talking about gummint regulation of industry, so this is not a solution that libertarians will like. See? Unfettered libertarianism will actually take away your freedom.

Naturally I share your feelings about this. Definitely let us give spirited throat to calls for our elected representatives to rectify this hi-tech iniquity.

But in the meantime, while we all politely wait for those august statesmen in the Capitol to get around to pretending to grapple with this matter, here’s a possible low-tech way you can make your cellphone completely undetectable to GPS snooping whenever you wish. It won’t harm your phone, it’s instantaneously reversible, you don’t need a shred of electronics knowhow, and it requires little if anything in the way of parting with the elusive spondulix.

Now, being the lazy but honest bum that I am, I feel at this point obliged to tell you that I haven’t dragged my ass out to go and actually test this method on a cellphone for myself. So even though I’m fully confident it will perform exactly as predicted and block the full spectrum of ordinary EMF and microwave radiation from either entering or leaving your phone, as a semi-devout empiricist, I must acknowledge that I can’t in good conscience absolutely, positively,100% swear to having personally witnessed its effectiveness.

But, I do know from firsthand experience that the exact same method works like gang-busters with walkie-talkies and CB radios. However, cellphones employ microwaves, which are much much smaller and far more tightly packed than radio frequencies, so just bear in mind that EMF shielding against microwave radiation has to be really “water-tight” so to speak, otherwise they’ll be leakage and you’ll have accomplished nothing.

Transporting your cell in a small metal case, like one of those old hinged flip-top, aluminum cigarette cases some guys back in the day used to like, would thoroughly block all microwave reception and transmission, including GPS tracking. Something comparable in size to an extra-large metal Band-Aid box would do the trick. But a nice looking, well-constructed, light-weight metal case could be a real pain to find and just as inconvenient to cart around.

Here’s one possibility I turned up.

On the other hand, you could cover a fabric cellphone pouch with panels of a fine copper or aluminum mesh, that you or one of your minions carefully cut out and tack-stitch in place by hand, taking pains to make sure the mesh covers the entire pouch and completely envelops the whole phone. Diligently modified in this manner, the pouch now acts as a Faraday-cage. When the phone is in the cage, which is to say inside the pouch, it will totally cut your phone off from receiving any and all incoming signals, including things like an urgent overseas call informing you that you’ve won the Irish Sweepstakes. So please for god sake proceed with caution! Assuming the sending strength of the phone’s GPS transmitter isn’t outrageously powerful, (most are surprisingly weak) the cocoon of fine metal mesh will either completely impede, or severely garble all outgoing signals, rendering you invisible to GPS tracking .

Here’s an example of a source for inexpensive, very fine aluminum mesh that appears as if it would serve this application admirably.

Of course before getting involved with all of that, you could for proof of concept purposes, simply fabricate a rough mock up, using plain old aluminum foil. Just remember, whether it be foil or mesh, it’s critically important that the phone be thoroughly encased on all sides by the EMF shielding.

Now that you’ve gone this far, why stop with your cell phone? -- An Inexpensive Method To Shield a Room Against Microwave Energy