"The Earls and Vernonia [U.S. Supreme Court] rulings show that minors have diminished privacy expectations relative to adults, especially when drug testing is implemented by individuals in a guardian or tutor capacity. Although not dispositive, Earls, Vernonia, and Chandler also illustrate that drug testing programs imposed on a subset of the population that has a 'demonstrated problem of drug abuse' may tilt the balancing test in the government’s favor, especially if the testing program is designed to effectively address the problem."
Carpenter, David H., "Constitutional Analysis of Suspicionless Drug Testing Requirements for the Receipt of Governmental Benefits," Congressional Research Service (Washington, DC: Library of Congress, January 19, 2012), p. 7.
http://www.fas.org/sgp/crs/mi…
