Paranoid Brain Storming: Stability of IMU and Position Security

I don’t want to be tracked. I am going to keep my Librem 5 phone in a Faraday pouch between calls. I am however concerned that the IMU in the phone would allow the calculation of my positions between calls.

  1. Is the IMU storing data? It seems like it would need to over some time frame for it to perform it’s basic function, but what is that time?: seconds, minutes, or hours?
  2. Is there a way to disable the IMU or clear it before the phone reaches out to cell phone towers?


Since you are not going to be using the phone between calls (as it is in a Faraday pouch), what about flipping all 3 switches, which turns off ALL sensors?


unless you want that modems-firmware firing radio at full power i suggest you ALSO make sure that ALL 3 kill-switches are in the ON position such that even when inside the “radio-jail” the L5 will be able to conserve power by NOT firing a stronger signal in an attempt to compensate for “no-signal-jail” …


IMUs themselves don’t store data, nor, generally, have any capacity for doing so. They’re simple sensor ICs that report values to the host. According to the specs, the Librem 5 uses a ST LSM9DS1. Note that the datasheet mentions nothing about persistent data storage. It can store 32 samples temporarily in a FIFO in RAM, but this is definitely not enough to compute a position history.

The host that reads it out might store data for calibration, but in the case of the Librem that code is open source so it should be possible to check.


Perfect. Thanks!

Make sure you’re grounded.

You’d need a pair of wires that connects from your cell phone holder down to your shoes and connects to metal tips on the soles and heels (both feet). Tap dancing shoes should do the trick. Men’s sock garters should keep the wires in place and hidden down your trousers.

Just don’t meet with the mafia. (Hey Tony, he’s wearing a wire!)

[Used last post, this is not at reC.]


IMU will tell whether you are moving and your orientation, but it won’t tell much of about your geolocation provided by the GNSS, which is what most spyware wants to track.

The Librem 5 will have software switches so you can turn off your GNSS and IMU, while still using the WiFi and/or cellular modem.

Of course, Google created a database of the range of WiFi networks and cellular towers when creating StreetView, so it has the ability to track your geolocation through the WiFi and/or cellular modem, even when the GNSS is turned off. If you have an app installed which uses Google’s Geolocation API, then Google can collect your geolocation data even if your GNSS is turned off. That is why it is best to stick to apps whose creators don’t have a business model based on monetizing people’s personal data.


Update: You can use the new carbon metal wires!

perfect !!! …

…has finally created the last tool in the toolbox, a metallic wire made entirely of carbon, setting the stage for a ramp-up in research to build carbon-based transistors and, ultimately, computers.*

TFW close enough to carbon-based computer already (not sure how it relates to the topic though) :smile:

It was for the guy with the Faraday pouch. A Faraday enclosure has to be grounded to work.

(I replied to the wrong guy though, my bad.)

nah it’s ok. i can see how the menacing face can be a reply magnet :sweat_smile:

I think that for frequencies of GHz and above, an ultracapacitor such as one of those, can replace the grounding requirement. Might even be an overkill, but the bigger, the better. There aren’t so big and heavy, after all (think AAA or AA batteries). And they are quite cheap, like $1 per 1F of capacitance.

Thanks, you can keep my joke about 3 Triple-A’s as the user replaceable battery for the Librem-5 alive.