Top Court In Massachusetts Says Cell Tower Dumps Are Constitutional (But Only With A Solid Warrant)
The Third Party doctrine has helped invert/pervert probable cause. Third parties (Google, AT&T, Facebook, etc.) gather tons of data that can be useful to law enforcement. When cops are looking for suspects but have no idea who to suspect, they turn to these third parties. In some cases, they can get plenty of data with nothing more than a subpoena.
In other cases, they use warrants. This seems like it's more respectful of the Fourth Amendment, but it generally isn't. Investigators use reverse warrants" to demand location data from Google, allowing them to work backwards from a long list of potential suspects to find the people they think they're looking for. Cell tower dumps are similar. Cell service providers turn over info on every phone connected to towers in the area during the time a crime was committed. Again, investigators don't know who they're looking for (yet), so everyone in the area is a suspect... at least until the data is examined further.
The inversion of probable cause is this: warrants are generally assumed to be particular to a place or person. These warrants have none of this particularity. All these warrants are particular" to is the data law enforcement wants access to. The only probable cause is the probability Google et al house the data investigators seek.
The Supreme Court of Massachusetts has been tangling with the constitutionality of these warrants for several months now. The state constitution has tended to be more protective of rights than the US Constitution, so that has added another wrinkle to the slow grind of the wheels of justice. The debate - being waged over cell towers dumps obtained with warrants - has finally come to an end.
Last December, oral arguments showed some of the state justices didn't necessarily believe the existence of a warrant okayed the general rummaging through cell service provider's records. In addition to the problem of the demand for records of everyone in the area, justices were concerned massive amounts of location data - especially when the records covered activities that occurred over several weeks - might be considered an unreasonable" search, even when warrants were used.
Five months after the oral arguments, the state Supreme Court tossed two of the seven warrants issued, stating that these were unsupported by probable cause. The other five remained in play, though, since they were more specific to the alleged crimes (six robberies and one related homicide). The court's interim ruling on those warrants noted the impact of the Supreme Court's Carpenter decision while making it clear it was not drawing a bright line that would make all similar cell tower dump warrants unconstitutional.
The ruling has arrived on the remaining warrants. As the EFF (which submitted an amicus brief in this case) reports, the court has found in favor of the other warrants, declaring them sufficiently compliant with both the state and US Constitution.
The court here held the police had sufficiently limited the scope of the search. Police had reason to believe the crimes were connected and committed by the same people, and police explained in their affidavit supporting the warrant that they had requested multiple tower dumps to look for commonalities among the records-phone numbers that appeared in more than one location.
Fortunately, thanks to its earlier ruling and stipulations made in this one [PDF], there are limits to how these warrants can be used. The court's guidelines require prompt and permanent disposal of unrelated cell site location info. And cops will need to obtain a warrant. Subpoenas are not an acceptable substitute.
Less fortunately, these restrictions won't do much to prevent Massachusetts law enforcement from deploying warrants to obtain massive amounts of location data, almost all of which will be entirely unrelated to the suspects they're seeking. There are some guardrails, but they're mostly meaningless because of how the court has chosen to define some key Fourth Amendment terms, as the EFF's Jennifer Lynch explains:
Perry could also have troubling implications for other dragnet search technologies like geofence warrants. The court asserted that the thousands of innocent individuals swept up in a tower dump are not subjected to a search" in the constitutional sense because, although police collected their data, police didn't take the further step of analyzing it.
But they had to analyze it. Otherwise, they wouldn't know what to discard as useless. A lot of this decision depends on judges deciding whether or not the warrant application is deficient. There's no bright line that says obtaining too much data is unconstitutional. It all depends on what law enforcement does with it after it already has it. So, it's a blend of judicial and law enforcement discretion and the judiciary being reliant on what law enforcement says it did or didn't do with the data. That won't deter abuse. And it leaves it up to criminal defendants to do the Constitutional heavy lifting while the courts stand by and let cops do what they've been doing.
Any process that allows law enforcement to collect tons of data using nothing more than the assertion that the targeted tech company houses this data needs to be subjected to more rigorous restrictions than what's been handed down here. At some point, the state's courts might actually make that happen. But today isn't that day.