Edward Snowden, Targeted Assassinations, and cell phone privacy

How private is your cellphone? How anyone can trace your location from your cellphone

Edward Snowden in the Guardian

This post is a reaction to the recent proof that Verizon (and presumably all other cellular operators) are providing the US government (NSA and private contractors like Booz Allen) with all your phone call metadata which, in the case of cell phones which almost everyone uses, include location information.

Osama bin Laden Courier Abu Ahmed al Kuwaiti found after cell phone call.

The targeted killing program has located and killed many of its targets because they made or received calls on their cell phones, including Osama bin Laden whose courier’s vehicle was identified and followed to the Abbottabad compound because of a cell phone call made by Kuwaiti as shown in a scene from the movie Zero Dark Thirty.

The book Digital Disconnect pointed out that smartphones should be called trackers because they allow the government and private corporations to track your movements.

Searches on the internet make it abundantly clear that the tracking capabilities of cell phones and the ability of governments and private companies to access this information is broadly misunderstood.

The author of this post is a retired engineer with more than ten years working with digital cellular networks and the technology that is now known as WIFI. Any errors in this information is his own.

All cell phone operators are able to trace the approximate location of the cell phone based on the cell that is currently being used during the call. Individual cell phones can be “heard” by more than one cell during use allowing cell phone operators to use the relative signal strengths (the number of bars on your phone) at each cell to calculate your actual real time location using triangulation. Because radio signals are affected by terrain, buildings, and other obstructions, using the cell phone signal strength to determine location is only an approximation. This approximation is usually good enough when the cell phone user is looking for a gas station or a restaurant or a landmark near his location. Smartphones target their searches based on location information.


Smartphones usually include GPS satellite receivers in their devices to enable the cell phone operator to know your exact location. The GPS is so accurate it can determine your location to within a few feet and if you are moving can determine your direction and speed with enough precision that the information could be used to accurately target a missile. The first basis of misunderstanding of the technology is that GPS signals are receive only. The location information from the GPS satellite must still be transmitted to a third party via ground wireless transmission and this requires a smartphone transmission to a central information collector using cellular frequencies or WIFI.

Smartphones have introduced a second independent communication technology, WIFI capability. Now your phone can be transmitting your location via the cell phone network or via WIFI. Since the range for WIFI transmissions is very limited, your WIFI location is within a few hundred yards of the WIFI node. So if your location is determined by the cell phone network, you can be located within a mile or so, if your location is determined by the WIFI node, your location can be known to within a few hundred yards, if your location is determined by GPS, you can be targeted to within a few feet.

If you don’t want your location monitored by third parties what can you do? If you want to use your phone to receive or send phone calls or use WIFI there is nothing you can do short of changing the law and enforcing that law. Sorry.

Can you “turn your phone off” as many web sites suggest? Short of removing the battery, no you can’t. When your screen goes dark, the phone has entered a battery saving standby mode where an incoming call can instantly wake the phone up. Is your phone transmitting location information while it “sleeps”? We don’t know but probably not as this would drain your battery, but the cell phone operator still retains the technical ability to get your location from a sleeping phone without alerting you should they wish to do so.

If you are also connected to a WIFI node things become even more complicated and a definitive answer probably depends on the phone provider software and on the applications that the provider or you have loaded into your phone. Generally, when the phone goes to sleep, WIFI is inoperable, but it is technically possible for a WIFI transmission to wake a sleeping phone without alerting the user. The technical problem is that a sleeping phone can be woken remotely. It depends on secret technical information unavailable to the user. As to downloaded applications anything goes. The Way of the Knife includes a story about Michael Furlong an overweight long time government and military contractor. He ran an operation where spyware was hidden in a cell phone game with information gathered and stored in an illegal database in the Czech Republic. You have no way to know what is hidden secretly inside the software the cell phone provider or you load to your cell phones.

Removing the SIM card may not prevent location transmission because of the emergency call requirements of cell phones in some countries including the US. Wikipedia reports that some US smartphones can make 911 calls without a SIM card. An inactive SIM card will not prevent you from making a 911 call on any cell phone but removing the card may or may not disable transmission. It depends on the phone model.

The assassination books noted that targeted terrorists routinely remove the SIM cards from their phones and use multiple SIM cards and multiple cell phones to avoid tracking, but the manufacturers and operators know this and could easily create phones that transmit location information without SIM cards if they wanted to. One would guess the US government is pressuring manufacturers to include this capability in all new cell phones. If a SIM card has been removed, the transmitted metadata would still include the unique identifier of the cell phone. Cell phones known to have been used by people on the US government’s targeted kill list have not only the phone numbers (associated with the SIM card) but the unique identifying numbers of the physical phones themselves. When one of the targeted cell phones is used, the information, including the location of the phone, is instantly available to the government assassination teams. Many assassinations have resulted from a phone call.

So the best bet at the moment to avoid transmission of tracking information in the US is to do two things:

1) Current Airline FAA regulations absolutely prohibit passengers from transmitting radio signals, specifically cell phone transmissions while flying. Consequently, most cell phones, including smart phones have an “airplane mode” which disables your cell phone transmission. Your cell phone will still allow the camera, music player, GPS and other features to function. So if you want to disappear from tracking monitors, just turn on your phone’s airplane mode.

2) If your phone has built in WIFI, you will need to turn it off to avoid location tracking. Strangely, the airlines are pressuring the FAA to allow the use of WIFI aboard their flights and this seems to be the new trend so turning on airplane mode still leaves WIFI functioning. How the FAA justifies allowing you to use WIFI but not cell phone transmission is one of those mysteries that have almost nothing to do with technology and may be carryovers from the distant past where old cell phone frequencies might interfere with aircraft communications. I doubt interference is possible today if it ever was a problem. Still airplane mode is one of the few remaining options if you want to use your cell phones for some functions while blocking cell phone transmission.

For a general discussion of metadata, the Guardian, which broke the Edward Snowden FISA authorization story posted this What is metadata guide. A recent blog post lists the information currently available and probably collected by the government and its contractors as NSA metadata.

Moyers and Lessig

For a great discussion of Snowden, Privacy, and Congressional corruption which prevents fixing our problems see Bill Moyers’ Big Brother’s Prying Eyes which aired on June 14, 2013.

Lawrence Lessig and Bill explore how we can protect our privacy when Big Government and Big Business morph into Big Brother.