Yep, Cellphone data spying: It's not just the NSA
Quote:
Stingray is a mobile device that masquerades as a cellphone tower... • About one in four law-enforcement agencies have used a tactic known as a "tower dump," which gives police data about the identity, activity and location of any phone that connects to the targeted cellphone towers over a set span of time, usually an hour or two. A typical dump covers multiple towers, and wireless providers, and can net information from thousands of phones. ...
The technology to find a cellphone in a remote area is out there, but it may not be active in the search & rescue business -- not that it couldn't necessarily be used in SAR. Then again, maybe they are using it but aren't making the capability known. You don't know what you don't know.