This is nonsense. There was a warrant, but the guy wanted the court to find that it was too broad. The warrant was for anyone who was a registered user at Playpen (the kiddie porn website in question). They didn't know it was his computer before they hacked it, they just knew it was the terminal used to log in to Playpen. He thought this was too broad.
From the court finding:
"NIT warrant described the places to be searched - activating computers of users or administrators that logged into Playpen - and the things to be seized - the seven pieces of information obtained from those activating computers - with particularity."
The court finding states that this super broad warrant did not violate the 4th. Can we please discuss that?