<blockquote>The reliability of drug dogs and their handlers is at the heart of a lawsuit filed in state district court by two Nevada Highway Patrol K-9 troopers and a consultant, who claim that the Metropolitan Police Department's police dogs, and eventually NHP's own dogs, were "trick ponies" that responded to their handlers' cues, and therefore routinely violated citizens' rights to lawful search under the Fourth Amendment.</blockquote>
via <a href="http://www.reviewjournal.com/news/crime-courts/legal-challenge-questions-reliability-police-dogs">Legal challenge questions reliability of police dogs | Las Vegas Review-Journal</a>.
<blockquote>Often the K-9 troopers were partnered with a drug task force that paired them with Las Vegas police narcotics detectives and that agency's K-9 dogs. They would go to a FedEx sorting facility where, the troopers allege, Las Vegas police detectives took packages from a sorting belt and poked holes in them so their dogs could better sniff for drugs inside. In one case, a detective tore open a package and searched its contents.

All of this was done without the consent of the owners of the packages, which would be illegal.</blockquote>