How to Make Your Own Faraday Cage (2024)

Protests against police brutality are currently taking place across the country, and while technology has been helpful in organizing them, it can also be used against those in attendance. Facial recognition can be used to identify (or misidentify, as often happens) protesters and phones can be surveilled.

If you're demonstrating, it's a smart idea to take steps to lock down your phone ahead of time or even just leave it at home. If the latter isn't possible, put it in a Faraday cage, an enclosure that shields against the entry or escape of electromagnetic fields.

A Faraday cage is useful for many circ*mstances. Perhaps you have a car with remote keyless entry, and want to prevent it fromgetting broken into by teens with a power amplifier. Or you don't want theNSA listening in on your conversations. Or you're a doomsday prepper just waiting for agigantic, Earth-enveloping electromagnetic pulseto rise up in the sky and wipe out all electronic communication.

You can buy Faraday cages that vary in size fromsmall bags that hold a smartphoneto aFaraday tentunder which you can park a car and probably your entire family.

If you'd rather not spend the money and think you can cook up a solution in your own kitchen using appliances, it's not that easy. It's commonly thought that a refrigerator or freezer can serve as an ersatz Faraday cage. But unless the seal is really tight, it's not likely to work. Likewise, a microwave oven also does not a Faraday cage make. A police precinct in Greenfield, Massachusetts, tried to prevent the remote wiping of phones it confiscated by placing them in microwave ovens. They found thatonly commercial-grade ovens worked.

There are still some things you might have on hand, though, that can be converted into a Faraday cage at little cost. Before you put your phone in one, though, put it in airplane mode, otherwise the battery will drain as it searches for a signal.

Think Small

If you're making a Faraday cage to take to a protest, your best bet is indeed to buy one. But you can make a small one.

The tinfoil hat joke comes from somewhere, and that somewhere is the Faraday cage. Aluminum foil can be used to protect against electromagnetic fields. Shoplifters use this to their advantage by coating the inside of bags to prevent detection. The same principle applies into this Instructables about using aluminum foil, an envelope, and some tape.

File It Away

A metal file cabinet requires just a few tweaks to be turned into a Faraday cage. Thesedirections on Instructablesrequire just a few common pieces of hardware, some cables, and the cabinet itself.

This Is All Garbage

The solution could be in your own backyard. Metal garbage cans—with a bit of modification—can be effective Faraday cages.

Shake It Off

If all this talk of Faraday cages is stressing you out and you want a drink, stop! Your easiest solution is at hand with a co*cktail shaker.

Testing 1-2-3

Whatever Faraday cage you choose, test it. Rigorous testing involves a software-defined radio receiver but you can do a simple test by tuning a radio to a station that comes in strong and placing it inside the Faraday cage. Close the cage and if you can still hear the station, the cage is not working.

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As an expert in technology and privacy, with a deep understanding of the challenges posed by surveillance and the protective measures one can take, I can provide valuable insights into the concepts discussed in the article.

The article highlights the ongoing protests against police brutality and the use of technology to both organize and potentially surveil protesters. The use of facial recognition and phone surveillance is emphasized, prompting the recommendation to secure personal devices during demonstrations.

  1. Facial Recognition Technology:

    • Facial recognition is mentioned as a tool used to identify protesters. It is crucial to understand that while this technology can be powerful, it is not infallible and often leads to misidentifications.
  2. Phone Surveillance:

    • The article warns about the surveillance of phones during protests. It advises individuals to take precautions such as locking down their phones or using Faraday cages to shield them from unwanted access.
  3. Faraday Cages:

    • A Faraday cage is introduced as a solution to protect electronic devices from electromagnetic fields. The article suggests using Faraday cages to secure phones during protests and provides information about commercially available options of various sizes.
  4. Faraday Cage Varieties:

    • The article mentions Faraday cages ranging from small bags for smartphones to larger tents that can accommodate a car and a family. This emphasizes the versatility of Faraday cages in different scenarios.
  5. DIY Faraday Cages:

    • The article explores do-it-yourself (DIY) options for Faraday cages. It dispels myths about using household items like refrigerators or microwave ovens and recommends more effective solutions like aluminum foil, metal file cabinets, and modified metal garbage cans.
  6. Testing Faraday Cages:

    • The importance of testing a Faraday cage is highlighted. The article suggests rigorous testing with a software-defined radio receiver but provides a simple test using a radio tuned to a strong station. If the station is still audible inside the cage, it indicates that the cage is not working effectively.
  7. Airplane Mode Precaution:

    • The article advises individuals to put their phones in airplane mode before placing them in a Faraday cage to prevent unnecessary battery drainage as the device searches for a signal.
  8. Commercial vs. DIY Faraday Cages:

    • While buying a Faraday cage is recommended for optimum protection, the article acknowledges that DIY solutions can be cost-effective. It provides options for those who prefer making their own Faraday cages using readily available materials.

In conclusion, the article serves as a comprehensive guide for individuals participating in protests, offering insights into the risks associated with technology and practical steps to protect personal devices from surveillance using Faraday cages.

How to Make Your Own Faraday Cage (2024)
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