http://magma.ua4vjlx72wv5crhkificaeysp62hizhazipfshsdvs6jxqvhtkpllcad.onion/guide/network-measurements.html
However, the rate of
decay of battery power of devices, when monitored over time, can allow for
differences to be found. While this type of monitoring would require significant
analysis, it is not beyond the bounds of possibility (and may be made possible
due to the perceived low sensitivity of gathering and releasing such data).