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An LAPD helicopter claimed to have ID'ed protesters from above and threatened to "come to your house"
(www.motherjones.com)
This is a most excellent place for technology news and articles.
Faraday cage does not prevent gyroscopes and accelerometers from working. Then if you remove it from a faraday cage in the future, it will transmit all that movement
Since you're posting this all over the thread, I'll also have to repeat the information that gyro/accelerometers are not capable of doing that. Small measurement errors stack up and throw it completely off.
Without GPS or tower based error correction any location prediction based on conservation of momentum in the phone will be useless before very long if the phone is moving.
Sounds theoretically possible I guess...