The Drugs people use can be traced in their urine, sweat, hair, saliva and blood. Despite the Fourth Amendment's clear guarantee of a right to privacy, courts have granted increasingly broad authority for random, suspicion less drug testing.
Various online forums and blogs pass along bad information about drug testing and attempt to give you bad advice about passing a drug test and leave people failing because the information was outdated or just not true.
As always, you need to stay alert and know the facts, because despite the popular joke, you really can study for a drug test. Wiki Drug Testing exist to bring you up to date information about drug testing and to answer any questions you may have created by a open community of users.