By: Cory McAlister
As Benjamin Smith mentioned in a recent post, the question of law enforcement’s use of “stingrays” in criminal investigations is currently being litigated in an Arizona federal court. A judge heard arguments on March 28 on the legal issues surrounding the FBI’s use of a Stingray to monitor Rigmaiden’s location.
Recall that Stingrays are international mobile subscriber identity (“IMSI”) catchers: they spoof the behavior of cell towers in order to trick local phones or other cellular devices into connecting through the Stingray rather than directly to a legitimate tower. Posts on this blog have alerted us to the power of cell site location information (“CSLI”),—the trafficking data collected by cell towers that reveals a caller’s whereabouts—which is permitted by most courts under the third party doctrine. The third party doctrine allows the government to demand records maintained by telecommunications companies necessary to the transmission of calls. A Stingray device allows law enforcement to bypass even the telecom’s (required) cooperation, and to pinpoint location with even greater accuracy than CSLI.
In Mr. Rigmaiden’s case, the FBI did in fact obtain a court order and warrant for mobile location tracking,—it appears to have been intended for obtaining CSLI—which they used to get information from Verizon Wireless about Rigmaiden’s use of an air card. They then tracked the location of his cell network-connected computer by setting up a Stingray to detect that air card’s use.
The defendant argued that the warrant application for the mobile location inadequately described the details of the technology that would eventually be used pursuant to the warrant, i.e. the Stingray. The defendant argued, therefore, that the FBI went beyond the scope of the warrant, and could not use any evidence obtained in excess of its authorization.
The government had originally argued in this case that the Stingray did not require a warrant of any kind, and therefore the details of the warrant application provided to the issuing magistrate had no bearing on its use. However, the government reversed course and subsequently argued that the warrant also authorized the use of the Stingray, and was sufficiently clear about the nature of the technology—that it would involve mobile location tracking—that the warrant could be validly issued.
As a separate matter, the defendant, and privacy advocates who submitted briefs as “friends of the court,” noted that the Stingray collaterally collected data from numerous innocent individuals who were not targets of the investigation. Rigmaiden does not have standing to contest the violations of third parties’ Fourth Amendment rights, but he argued that the warrant as a whole is defective because it did not meet the Fourth Amendment’s particularity requirements. That is, even if the scope of the warrant encompassed the use of the Stingray, that scope would mean so broad a search that it amounts to an invalid general warrant. The government, for its part, countered the defense’s particularity claims by arguing that it purges data on individuals unrelated to the investigation, and thereby allays the particularity concerns.
http://www.wired.com/threatlevel/2013/03/gov-fights-stingray-case/all/