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Government Surveillance

4th Amendment Victory in Cell Phone Tracking Case

Last year, the ACLU, joined by CDT, EFF and NACDL, filed an amicus brief in the federal Court of Appeals for the 11th Circuit, arguing that government access to stored cell site location records is a search that requires a warrant.

Yesterday, the Court of Appeals agreed.  Applying the Leon good faith exception test, the court declined to overturn the appellant’s convictions obtained using the cell site information, but the opinion is a strong, unprecedented extension of Fourth Amendment rights.

To begin with, the court was heavily influenced by US v. Jones, the Supreme Court’s 2012 decision holding that extended use of a GPS device to track someone was a search under the Fourth Amendment: “While Jones is distinguishable from the case before us, it concerned location information obtained by a technology sufficiently similar to that furnished in the cell site location information to make it clearly relevant to our analysis.”

Remarkably, the appeals court said, ‘even one point of cell site data can be within the reasonable expectation of privacy.’

Summarizing Jones, and the historical distinction between the trespass theory of the Fourth Amendment and the privacy theory, the court concluded that the privacy theory applied to cell site location information.  On this basis, the appeals court concluded, “that the appellant correctly asserts that the government’s warrantless gathering of his cell site location information violated his reasonable expectation of privacy.”

The court addressed the government’s claim that cell site information was factually distinguishable from the GPS data at issue in Jones.  The court agreed that it was distinguishable, but it said, “we believe the distinctions operate against the government’s case rather than in favor of it.”  Whereas the government in Jones had used the GPS device to track someone’s movements only on the public streets, the cell phone, the court noted, “can accompany its owner everywhere.”

Remarkably, the appeals court said, “even one point of cell site data can be within the reasonable expectation of privacy”: “When one’s whereabouts are not public, then one may have a reasonable expectation of privacy in those whereabouts. Therefore, while it may be the case that even in light of the Jones opinion, GPS location information on an automobile would be protected only in the case of aggregated data, even one point of cell site location data can be within a reasonable expectation of privacy. In that sense, cell site data is more like communications data than it is like GPS information. That is, it is private in nature rather than being public data that warrants privacy protection only when its collection creates a sufficient mosaic to expose that which would otherwise be private.”

The government argued that cell site data is less precise than GPS data.  The appeals court said it didn’t see the constitutional significance in precision, citing the prosecutor’s insistent reliance on the data to associate the appellant with the crimes charged.

Finally, the court rejected the government’s Smith v. Maryland argument.  The court found that cell site information was not knowingly and voluntarily surrendered to the service provider.

The court concluded: “In short, we hold that cell site location information is within the subscriber’s reasonable expectation of privacy. The obtaining of that data without a warrant is a Fourth Amendment violation.”