The backside of the device seems to contain some sort of rolling counter that likely either keeps track of call duration or gives you the time.
There was also said to be significant help from regional allies, Jordan and Turkey, and tracking of telephone calls to Kuwait where Emwazi's Iraqi-born parents live.
In a separate development, New York District Judge William Pauley dismissed on 27 December a lawsuit filed by the ACLU in June, which claimed that the way the NSA tracked million of calls contravened the US constitution.
Trends may be inferred from data that is believed to be related to the measure of interest, but in unknown ways, such as tracking the effect of economic changes on mental health by tracking the number of calls to hotlines.
Until recently, the Baby Bells had a difficult time of tracking what percentage of calls were intrastate or interstate.
If tracking the location of a car over time is regulated by the Fourth Amendment, as five Justices suggested in Jones, why shouldn't tracking the location of calls receive the same treatment?
Some handle everyday tasks, keeping track of telephone calls and voice mail messages.
An Israeli television station kept track of the calls up to 5,000, and then quit.
Many forces do not have a system for keeping track of repeat calls, so cannot easily say who the most dangerous repeat perpetrators are.
