[aerosuch]

According to the state ruling, the "device" in question is an "I phone" https://www.documentcloud.org/documents/408509-massachusetts...

It uses some technology (circa 1978) called "GPS".

We're living in the future!

[revelation]

Quite frankly, I wouldn't certify that. Measuring based on data derived from the GPS chip (not the raw data), always at the mercy of the operating system not to hibernate your app.