The Justice Department has filed a petition for rehearing en banc in United States v. Davis, the Eleventh Circuit case holding that acquiring historical cell-site data is a Fourth Amendment search. I hope the Eleventh Circuit grants rehearing for the reasons suggested in this post.

A few excerpts from my earlier post:

The more I think about Davis, the more radical a reinterpretation of the Fourth Amendment it seems to be. If we take its analysis seriously, I’m not sure I know what police investigations are still constitutional.

[Davis‘s] approach is really different from traditional Fourth Amendment analysis. In the old days of the Fourth Amendment — before August 6, 2010, when the DC Circuit decided Maynard — the search inquiry of the Fourth Amendment hewed pretty closely to the basic idea of physical intrusion. The Katz inquiry permitted surveillance that was not a technical intrusion to count as a search. But as a practical matter, interpretations of Katz followed the basic distinction between surveillance that broke inside private spaces (a search) and surveillance that merely observed what occurred in public (not a search).

Davis replaces that tradition with a more generalized notion that a search occurs when something that seems to the judges like a privacy invasion appears to have occurred. Depending on how you look at the Fourth Amendment, this is either a “look ma no hands” free-form departure from text, history, and precedent or else a welcome turn towards the true Constitution that the Warren Court promised in Katz but that the Supreme Court later failed to deliver. Either way, it seems really hard to know how to apply the more generalized privacy invasion standard. It’s hard for me to say what police techniques are searches if the analysis in Davis is correct.

[Plus], even if you accept the Eleventh Circuit’s basic theory, its application to cell-site records strikes me as very puzzling.

I tend to think the Eleventh Circuit was wrong as to the result, too, which makes it an easy case for rehearing. But even if you think the result was right, it would be very helpful to other courts and to future Supreme Court review if the Eleventh Circuit explained what it was thinking better than the panel opinion did.