In the case U.S. v. Zachary Austin Halgren, Judge Xavier Rodriguez has denied the defense's request to suppress evidence obtained via an FBI network investigative technique.
In the case U.S. v. Zachary Austin Halgren, Judge Xavier Rodriguez has denied the defense's request to suppress evidence obtained via an FBI network investigative technique.

Weighing in on the FBI's use of malware to identify and arrest users of the dark web child pornography site Playpen, a Texas federal judge last week ruled in favor of the U.S. Department of Justice, rejecting a motion to suppress evidence obtained in the course of the investigation.

In 2015, the FBI in Virginia secretly took over a server used by Playpen and used what the agency calls a network investigative technique (NIT) -- more commonly known as malware -- to track the IP addresses of individuals querying this server. Among the alleged Playpen visitors who were subsequently identified and arrested were Zachary Halgren of San Antonio, Tex. -- the defendant in this case.

Western Texas U.S. District Court Judge Xavier Rodriguez ruled that the warrant the FBI obtained from a local magistrate judge to implant the NIT was not too broad in its scope to violate the Fourth Amendment's particularity requirement.

While Rodriguez agreed that under the laws of 2015, local magistrate judges were prohibited from issuing warrants to collect evidence located outside their jurisdictions, he noted that an exception applied to tracking devices that were initially installed in the magistrate's district, only to move outside the jurisdiction along with the individual under surveillance. Rodriguez opined that this scenario was "exactly analogous to what the NIT Warrant authorized," in that the defendant's computer allegedly contacted an FBI-controlled server in Virginia, which tracked the device back to its location in Texas.

The judge also ruled that the defendant "lacked a reasonable expectation of privacy in his IP address when using the internet" and allegedly accessing the Playpen website. And even if Halgren did have a reasonable expectation of privacy, or the local magistrate judge did exceed her jurisdictional authority, the "good faith" exception would still apply to the search of the defendant's property.

Finally, the judge rules that the affidavit used to establish probable cause for the search did not contain misrepresentations.

The legality of FBI investigations relying on an NIT warrant has been closely scrutinized in recent years, with courts in different jurisdictions issuing conflicting rulings. Earlier this month, a federal judge in Minnesota ruled that the FBI exceeded the scope of the Virginia magistrate's Playpen search warrant, but did not suppress evidence in the case because he believed the agency acted in good faith.

In April 2016, a Massachusetts federal court judge did suppress evidence in another Playpen case, after ruling that the Eastern Virginia magistrate overstepped her authority. One month later, a Washington State judge also tossed evidence in a Playpen case because the FBI refused to disclose the NIT code used to obtain the evidence. And in another case, a judge in Eastern Virginia sided definitively with U.S. law enforcement, ruling that investigators do not even need a warrant to remotely hack into suspects' computers.