Most jobs involve contact with the public and come with the potential for life threatening situations. Even people working at McDonalds could burn the place down so I totally see where you're coming from. I'm personally off the opinion recreational drug use has no place in the workplace regardless of your occupation but obviously there is going to be a bit more of a concern about a bus driver being under the influence than some 16yo kid making you a cheeseburger while high. A persons drug use shouldn't interfere with their employment but that goes both ways because while we shouldn't expect to lose employment because of private drug use employers should have the right to expect their workers to be sober on the job. It's like being clean groomed and on time, if its a part of the job it should just be expected of them and breaking that rule should be grounds for termination because they're unfit to do their job but that should never give all employers the right to drug test the people working for them. Having said that though I think some occupations should have a zero tolerance approach and have mandatory drug testing because it would be in the public interest to do so. Doctors, politicians, police, etc. all have the potential to cause massive harm and even deaths on a large scale in the case of politicians so certain occupations should definitely be held to a higher standard than others. The hard thing to do is apply commonsense to the list of jobs that require absolute sobriety as there will always be someone belly aching out of self interest, the belief in privacy above all else, etc. but their gripes shouldn't hold any weight against the rest of society. A surgeon crying about his privacy for example should have dreamed of being sober while in that life and death situation where they play god as you can be damn sure everyone they work on expects them to be sober for it. I doubt you could even find a person that would genuinely let a surgeon anywhere near them if they were even slightly off their game from drug use a few days prior so it would be in the public interest to make that a sober occupation. The same could never apply to things like working in an office, retail, restaurants, etc. so as long as the people working in them live up to the requirement of being sober on the job their private use would never be an issue.