Back in July, a small but disturbing detail on the government's cell phone tracking abilities was buried inside a larger story detailing the explosive expansion of the NSA post-9/11. Ryan Gallagher at Slate pulled this small paragraph out and highlighted it.
By September 2004, the NSA had developed a technique that was dubbed “The Find” by special operations officers. The technique, the Post reports, was used in Iraq and “enabled the agency to find cellphones even when they were turned off.” This helped identify “thousands of new targets, including members of a burgeoning al-Qaeda-sponsored insurgency in Iraq,” according to members of the special operations unit interviewed by the Post.
Ars Technica reports that some security researchers are calling this statement into question
and have contacted cell phone providers for statements on the NSA's claim. Only a few have responded at this point, and their denials have been worded very specifically
Google had this to say:
When a mobile device running the Android Operating System is powered off, there is no part of the Operating System that remains on or emits a signal. Google has no way to turn on a device remotely.
may not have a way, but that doesn't mean the NSA
Our devices are designed so that when they are switched off, the radio transceivers within the devices should be powered off. We are not aware of any way they could be re-activated until the user switches the device on again. We believe that this means that the device could not be tracked in the manner suggested in the article you referenced.
Once again, we're looking at words like "should" and "not aware." This doesn't necessarily suggest Nokia does
know of methods government agencies could use to track phones that are off, but it doesn't entirely rule it out either.
is more interesting. While declaring that all components should
be turned off when the phone is powered down, it does acknowledge that malware could trick cell phone users into believing their phone is powered down when it isn't. Ericsson, which is no longer in the business of producing cell phones (and presumably has less to lose by being forthright), was even more expansive
on the subject.
The only electronics normally remaining in operation are the crystal that keeps track of time and some functionality sensing on-button and charger connection. The modem (the cellular communication part) cannot turn on by itself. It is not powered in off-state. Power and clock distribution to the modem is controlled by the application processor in the mobile phone. The application processor only turns on if the user pushes the on-switch. There could, however, be potential risks that once the phone runs there could be means to construct malicious applications that can exploit the phone.
On the plus side, the responding manufacturers seem to be interested in ensuring a powered down phone is actually powered down, rather than just put into a "standby" or "hibernation" mode that could potentially lead to exploitation. But the implicit statement these carefully worded denials make is that anything's possible. Not being directly "aware" of something isn't the same thing as a denial.
Even if the odds seem very low that the NSA can track a powered down cell phone, the last few months of leaks have shown the agency has some very surprising capabilities -- some of which even stunned engineers
working for the companies it surreptitiously slurped data from.
Not only that, but there's historical evidence via court cases that shows the FBI has used others' phones as eavesdropping devices by remotely activating them and using the mic to record conversations. As was noted by c|net back in 2006
, whatever the FBI utilized apparently worked even when phones were shut off.
The surveillance technique came to light in an opinion published this week by U.S. District Judge Lewis Kaplan. He ruled that the "roving bug" was legal because federal wiretapping law is broad enough to permit eavesdropping even of conversations that take place near a suspect's cell phone.
Kaplan's opinion said that the eavesdropping technique "functioned whether the phone was powered on or off." Some handsets can't be fully powered down without removing the battery; for instance, some Nokia models will wake up when turned off if an alarm is set.
While the Genovese crime family prosecution appears to be the first time a remote-eavesdropping mechanism has been used in a criminal case, the technique has been discussed in security circles for years.
Short of pulling out the battery (notably not
an option in some phones), there seems to be little anyone can do to prevent the device from being tracked and/or used as a listening device. The responding companies listed above have somewhat hedged their answers to the researcher's questions, most likely not out of any deference to government intelligence agencies, but rather to prevent looking ignorant later if (or when) subsequent leaks make these tactics public knowledge.
Any powered up cell phone performs a lot of legwork for intelligence agencies, supplying a steady stream of location and communications data. If nothing else, the leaks have proven the NSA (and to a slightly lesser extent, the FBI) has an unquenchable thirst for data. If such exploits exist (and they seem to), it would be ridiculous to believe they aren't being used to their fullest extent.