Earlier today, I linked to a post by Orin Kerr asking what happens when data collection occurs in two different judicial districts that may have different Fourth Amendment standards for whether a warrant is required. A recent post by Hanni Fakhoury of EFF addresses some of the same issues, writing, in part:
The Fourth Amendment is the law throughout the country, binding both federal and state law enforcement. While states are free to interpret their state constitutions or enact laws that impose stronger legal protections than those in the Fourth Amendment, they cannot provide weaker privacy protections. So, once a federal appeals court issues a ruling that requires state and federal law enforcement in one part of the country to use a warrant, it would be inconsistent to permit officers in other parts of the country to use weaker legal process to get those same records. The Fourth Amendment must mean the same thing everywhere and not vary from state to state; inconsistencies reduce legal protections for some people and tempts officers from a more restrictive jurisdiction to see if their counterparts in a less restrictive jurisdiction can get the records for them instead.
Today there are clear inconsistencies in the application of the Fourth Amendment to cell tracking. While a police officer in Mississippi can claim that she does not need a warrant to obtain cell site records under the Fifth Circuit’s decision, her counterpart in the neighboring state of Alabama clearly does under Davis. Instead of waiting for the Supreme Court to resolve this split, right now mobile phone network operators should follow the lead that major communication providers set after Warshak and make Davis the standard nationwide, requiring all law enforcement across the country use a search warrant to obtain cell site location information.
Read more on EFF.