Fourth Circuit weighs in on "Playpen" cases

US v. McLamb:  In this appeal, the Fourth Circuit considered whether the defendant’s motion to suppress evidence was properly denied for an invalid warrant obtained by the FBI in its investigation of a child pornography website known as “Playpen,” a hidden services message board located on the “dark web.”   After seizing Playpen’s servers, the FBI sought a warrant to deploy the Network Investigative Technique (“NIT”) to locate Playpen’s users.  A federal magistrate judge issued the warrant, authorizing use of the NIT on Playpen visitors for 30 days.  The NIT identified thousands of computers across the world that accessed Playpen during this month-long period.  McLamb was one of those thousands.  He moved to suppress evidence on his computer as the fruit of an invalid warrant, challenging the warrant’s particularity and its execution, as well as the jurisdiction of the magistrate who authorized the search.  The district court denied McLamb’s motion, and the Fourth Circuit affirmed, finding that even if the warrant was unconstitutional, the district court properly denied the motion to suppress because the good faith exception from Leon applies. 
Three other circuits (Eighth, First, and Tenth) have analyzed the same NIT warrant at issue here, and each has concluded that even if the warrant violates the Fourth Amendment, the Leon good faith exception precludes the suppression of evidence.  The Fourth Circuit agreed.