Document Freed By FOIA Shows How Much Data The FBI Can Obtain From Cellphone Service Providers

from the quite-a-bit-and-dating-back-for-quite-awhile dept

An internal FBI document shared with Joseph Cox of Motherboard by Ryan Shapiro of Property of the People gives a little more insight into law enforcement's data grabs. The Third Party Doctrine -- ushered into law by the Supreme Court decision that said anything voluntarily shared with third parties could be obtained without a warrant -- still governs a lot of these collections.

For everything else, there are warrant exceptions, plain view, inevitable discovery, a variety of "exigent circumstances," and reverse warrants that convert probable cause to "round up everyone and we'll decide who the 'usual suspects' are." Constitutional concerns still reside in this gray area, which means law enforcement will grab everything it can until precedent says it can't.

The document [PDF] gives some insight into the FBI's CAST (Cellular Analysis Survey Team). It shows how much the FBI has access to, how much it has the potential to grab, and how much unsettled law aids in bulk collection of data the FBI can parse through to find suspects or, if enough fishing rods are present, decide whether it has anything to do with its investigative time.

It's all in there, starting with "Basic Cellular Theory" and moving on to everything cell-related the FBI can get its data mitts on.

CAST supports the FBI as well as state, local, and tribal law enforcement investigations through the analysis of call data and tower information, the presentation adds. That can include obtaining the data from telecommunications companies in the first place; analyzing tower dumps that can show which phones were in an approximate location at a given time; providing expert witness testimony; and performing drive tests to verify the actual coverage of a cell tower.

More specifically:

CAST will utilize industry standard survey gear drive test equipment to determine the true geographical coverage breadth of a cell site sector...

Hell yeah. Mapping the frontier except its a van full of feds out wardriving, Lewis-and-Clarking their way into OTA superiority.

Other information derived or directly included in this presentation shows CAST (and?) crew are leveraging minimal oversight and precedent to hoover up data, including historical cell site location data, which now has some constitutional protection. One CAST member Vice found on LinkedIn noted their "special emphasis" on long-term tracking via historical cell site data, apparently occasionally in service of solving serious crimes.

To that end, the FBI apparently operates its own software to help collect data from cell towers and cross reference it with whatever the agency can collect from other sources.

“CASTViz has the ability to quickly plot call detail records and tower data for lead generation and investigative purposes…"

There's more to it. A lot of what's discussed here has been discussed in the public sphere (courts, records requests, leaked documents, etc.), but even if the subject matter is familiar, it's entertaining and educational to see the FBI's (instructional) take on what is now a large part of current Fourth Amendment jurisprudence. It discusses everything from grabbing location data from burner phones to General Motors' OnStar in-vehicle systems.

The document also makes it clear not all service providers are created equal. Some are far more useful than others.

The presentation provides more recent figures on how long telecoms retain data for. AT&T holds onto data such as call records, cell site, and tower dumps for 7 years. T-Mobile holds similar information for 2 years, and Verizon holds it for 1 year.

The slide also shows that AT&T retains “cloud storage internet/web browsing” data for 1 year.

AT&T has always been proactive with its data-sharing. It has set up its own data centers where NSA analysts can grab communications and other data from AT&T internet backbones. This is on top of whatever it can offer on the telco side, including its millions of cell phone users. There are eight of these secret data centers in the United States. All of this helps explain why AT&T holds on to so much data for so long: it has plenty of federal customers to give it to.

There's also some discussion of real-time tracking, which is governed by far fewer precedential decisions. The DOJ enacted a warrant requirement (with plenty of exceptions) for Stingray device use, but hasn't done the same for real-time tracking via cell service providers. As it stands now, the Third Party Doctrine is controlling, which means warrants aren't needed and if it's a close call, a variety of exceptions would likely make use of these tools a "good faith" effort, legally speaking.

It's a good peek into the FBI's data collection habits, one that also shows how much cell providers collect and retain, which may provide guidance for privacy-minded individuals in the market for a new service provider.

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Filed Under: cast, data, fbi, foia, privacy