One major concern, said Witmer-Rich, is that the warrants are at odds with the Fourth Amendment. That guarantees American citizens “the right of people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.”

“Just the fact that the government is in your house, or in your business, and you don’t know that they’re there, is a real privacy invasion,” Witmer-Rich said. “The whole idea of the Fourth Amendment is that some places in our lives, we can retreat back to our homes. We can relax. We can be ourselves and the government’s not in there, they’re not watching us. A covert search warrant really changes that calculus.”

Witmer-Rich also said that using video surveillance to catch customers soliciting prostitution, a misdemeanor, is tangential to proving human trafficking, a felony.

“Recording the sex acts themselves doesn’t really get you the evidence you need for human trafficking,” Witmer-Rich said.

He said the Supreme Court has never taken a case deciding the constitutionality of sneak-and-peek warrants.

The court ruled, though, in a 1979 case involving the theft of stolen goods meant for interstate commerce, that covert entry is constitutional in some circumstances. The Fourth Amendment does not prohibit per se a covert entry performed for the purpose of installing otherwise legal electronic bugging equipment, the court found.

The court also ruled in a 1990 drug case that delaying notice of a search warrant is permissible if there is “good reason.”