https://www.wired.com/story/how-wily-teens-outwit-bathroom-vape-detectors/

Last spring, students at Hinsdale Central High School discovered six vaping detectors in bathrooms and locker rooms around campus. About 20 miles south-west of Chicago, Hinsdale Central has been battling on-campus vaping for years: Administrators tried making students take online courses if they were caught with e-cigarettes; they talked to law enforcement; the Village of Hinsdale even passed an ordinance that would make it easier for officers to ticket minors caught with the devices. To no avail. And the detectors? Students simply ripped them off the walls.

E-cigarettes, which are easy to conceal and, until recently, came in a dazzling array of sweet, fruity, and dessert flavors, are hugely popular among teenagers. A recent study found that 28 percent of high schoolers and 11 percent of middle schoolers frequently vape. So schools across the country are spending thousands of dollars to outfit their campuses with vaping detectors, only to find that the devices can’t stand up to wily teens and that policing student behavior isn’t the same as permanently changing it.