The Carpenter Adjustment

Chapter 9 of "The Digital Fourth Amendment"

With the Supreme Court set to hear oral argument on April 27th in United States v. Chatrie, the geofence warrant case, I'm pleased to be able to post The Carpenter Adjustment, which is Chapter 9 of my 2025 book, The Digital Fourth Amendment.  In the chapter, I explain what I think Carpenter means, the moves it is making, and how I think courts should interpret it.  You can read the chapter here.

Here's the chapter summary:

The chapter considers how courts should interpret Carpenter v. United States (2018), the Supreme Court's blockbuster ruling that cell-site location records are protected under the Fourth Amendment. Carpenter is the Supreme Court's equilibrium-adjustment for noncontent network information: it recognizes that some network metadata is new and that the translation from physical space to network environments should treat some metadata differently. The question is, Which Internet data qualifies? This chapter develops a three-part test to apply Carpenter to Internet information. It then applies the test to a few important types of Internet information, such as Internet protocol addresses, geofence warrants, trip information, and Google search terms.

Ideally one would read this chapter in the context of the entire book, but I think this 20-page chapter stands on its own relatively well.

Comments

[Dr. Ed 2]

I would at least draw the fence with a stingray — I may be consenting for my Telco provider to keep track of where my cell phone is as it’s necessary to make it work.

I am NOT consenting to other people (i.e. the police) the fraudulently access it under fraudulent circumstances. In theory, the police could call me and get a copy of the record of what cell phone tower my phone connected to for that call, and that might be acceptable, although I doubt it, but how is a stingray not a textbook example of fraud?

And yes, I’m being harmed. It is using my limited battery time, and is degrading the quality of my service as any calls. My call has to go through their device and then their connection to the POTS backbone, and both resources, and the speed of light are finite.

Does anyone know how many drop calls are caused by stingrays? Does anybody outside of law-enforcement even know???

Likewise, how many times do I have five bars and no service or “911-only” service because the stingray is busy and not the actual cell tower. Again, does anyone outside law-enforcement even know?!?

I’m not doing anything I need to hide, but if I can be criminally prosecuted for stealing cable TV service then why can’t the cops be criminally prosecuted for stealing my cell phone service? It is the fifth amendment and not the fourth amendment here.