When the local drug dog shows up to sniff lockers, cars, and backpacks at Temple City High School in Southern California, senior Jonathan Huynh takes immediate notice. His heart rate jumps, his breathing slows, his hands start to sweat.

But Huynh isn't nervous because he has something to hide. His wariness stems from firsthand knowledge that drug dogs aren't the infallible sniffing machines imagined by the U.S. Supreme Court and much of the public. When Huynh was an eighth-grader at Oak Avenue Intermediate School in Temple City, a drug dog picked out his gym locker during a random search. When Huynh returned to the locker room at the end of class, a school administrator opened his locker in front of him and the rest of his classmates. The detection dog immediately lunged for the backpack and took hold of it, but when the administrator subsequently searched it, he found no drugs or other contraband. When the administrator and the canine team left, all the other students started laughing at Huynh. "I felt completely humiliated," he later wrote on an online message board.

The Temple City Unified School District contracts with a local franchise of a company called Interquest Detection Canines to conduct 17 inspections a year at three schools in its district. Ever since junior high, Huynh and his fellow classmates have lived under the threat of random canine sweeps.

In this respect, they're not that much different from millions of other Americans. Olfactory eavesdropping is a boom industry. "I've heard that there are as many as 18,000 police service dogs working in this country, doing narcotics control, explosives, tracking," says Terry Anderson, president of the National Police Canine Association, an organization that trains and certifies police dogs and their handlers. But while these police dogs and their counterparts in the private sector bury their super-sensitive snouts into our business, who's watching them? Certification is largely optional. "There's only two states in this country that say if you want to have a police dog, these are the criteria you have to meet," says Anderson, who also serves as a police officer in Pasadena, Texas.

While neither the federal government nor most states impose or even suggest standards for selecting, training, or evaluating detection dogs, the highest courts of the land give them plenty of leash when it comes to privacy rights. That started in 1983, when Justice Sandra Day O'Connor wrote in U.S. v. Place that a canine sniff of luggage at an airport is so limited—in both its intrusiveness and in what it could disclose—that it doesn't qualify as a search within the meaning of the Fourth Amendment, which bars "unreasonable searches and seizures." A detection dog would only alert if a piece of luggage contained contraband, O'Connor opined, and contraband wasn't subject to privacy protections.

Since then we've learned that detection dogs aren't infallible. During a 1994 search that took place at a high school in Harborcreek Township, Pennsylvania, for example, a drug dog sniffed 2,000 school lockers and indicated that 18 of them contained contraband. Only one actually did.

Such incidents have done little to damage the reputation of drug dogs among the animal lovers on the Supreme Court. In the 2005 case Illinois v. Caballes, the Court ruled that a canine sniff for narcotics at a traffic stop was not a search, even when there was no reasonable cause for suspicion. In writing the opinion for the majority, Justice John Paul Stevens further enhanced the power of drug dogs by claiming that even their false alerts are no cause for concern, because no "legitimate private information" is conveyed when they indicate the presence or absence of contraband material.

But if a false alert reveals no legitimate private information, it does pave the way for a search that can do exactly that. In a 2005 essay for the NYU Journal of Law & Liberty, criminal defense attorney Ken Lammers translated Justice Stevens' dubious argument into plainer language: "It is as if Justice Stevens had upheld a warrant by arguing: 'When Officer Smith lied to Judge Jones in order to get the warrant, the lie, in and of itself, did not reveal any legitimate private information, and therefore the warrant is valid.'?"

Imagine a world where meter maids provisioned with drug dogs routinely check your car for cocaine, where postal carriers and their drug dogs give your front porch a good going-over on occasion. This, essentially, is what Illinois v. Caballes makes possible, and as Lammers noted in his essay, "these types of canine searches are already taking place." The venue? Schools like Temple City High.

In 2007, Temple City High made Newsweek's list of America's best high schools. In January 2010, representatives from Interquest giving a presentation at the local Kiwanis Club characterized Temple City Unified School District as "one of the cleanest" districts they serve. When I spoke with Scott Edmonds, president of the local Interquest franchise, he said that during visits to Temple City his canine inspection teams indicated the presence of drugs at a rate that was "well below the average for a public school district."

"We don't have a drug problem," Temple City senior Mark Lamb tells me. And yet in November 2010, two inspections occurred at the school within the span of two weeks. That's when Lamb, Huynh, and a handful of other students began trying to change school policy. Their focus is the backpack inspections. In these, a school administrator enters a randomly chosen classroom, tells students to leave their backpacks and other personal effects on their desks, then makes them move to another part of the room or, in some instances, leave the room entirely while a dog sniffs at their possessions.

In the 1999 case B.C. v. Plumas, the U.S. Court of Appeals for the 9th Circuit (which includes California) held that similar random and suspicionless inspections that took place at a high school were unreasonable searches in part because school administrators had failed to establish that there was a "drug crisis" or even a "drug problem" at the school. The following year, the state's attorney general at the time, Bill Lockyer, issued an opinion that reached similar conclusions.

Of course, these conclusions were reached prior to Illinois v. Caballes. But while the Supreme Court has now deemed random, suspicionless sniffs constitutionally correct, what of the seizures that sometimes occur as a prelude to these inspections?

In March 2010, the Third Court of Appeals of Texas held that a student who was forced to leave her backpack on her desk for a drug dog to sniff after she and other students vacated the room had not been victim of an unreasonable seizure because that seizure did not lead to a significant invasion of privacy. But a seizure doesn't have to compromise someone's privacy to qualify as unreasonable—it just has to be unreasonable. "Consider an officer walking up to you on the street and grabbing your briefcase out of your hand," attorney Ken Lammers writes in an email to me. "He has seized it, but he has no idea what is inside it and therefore your privacy has not been infringed upon. [But] would a reasonable person believe your constitutional right against unreasonable seizure of your property had been violated? Of course he would."

So far, Lamb and Huynh have been unable to convince their school that their rights are being violated. But they haven't given up yet. They're hoping to enlist the help of the American Civil Liberties Union or some similar legal organization, and they plan to make their case for canceling the contract with Interquest at an upcoming meeting of their district's school board.

"They all wore suit jackets," Interquest president Scott Edmonds told me after meeting with them to discuss the inspections. "They were nice kids." But these days even nice kids get treated like potentially dangerous prisoners.

Contributing Editor Greg Beato (gbeato@soundbitten.com) writes from San Francisco.