Other: Whoever voluntarily agrees to be drug tested as part of any contract free of coercion. At any point in time, they should be able to sever the contract, rather than be tested, though. This basically means they can walk off the job. One catch, though. If they agree to be "drug free" in a free society, and an incident occurs, it's probably in their best interest to voluntarily be tested, to get "off the hook" for any claim. If they don't agree to such a test, they can expect the claims to be made and their reputation to be sullied.