Is Drug Testing an Invasion of Privacy
Like so many questions in today's world, this isn't a question that can be judged simply as black and white, right or wrong. Is it an invasion of a person's privacy? Without a doubt. You are basically accusing a person of using illegal drugs and making them prove that they are not. This is reminiscent of the Napoleonic Law Codes. Guilty until you can prove your innocence.
Is it a necessary evil? In many cases it can be. It depends on which side of the fence you happen to reside on. Most employers require you to pass a drug screen at two times. First when you get hired, and second if you happen to get hurt on the job. These two times are understandable. In the first example, an employer can (in theory) weed out an undesirable employee that is a drug user. This can cut down on mistakes at work as well as absenteeism. The second point, which is if you get hurt and therefore have a workers compensation claim, the drug test will help the employer cut down on the premiums that they have to pay for that particular type of employee insurance. The down side to that point is that if you happened to smoke marijuana two weeks before the accident, yet the test is positive, it is assumed that you were under the influence when you had the accident. This will in effect make you liable for said accident. That means no compensation as well as losing your job and possible criminal charges.
As stated earlier, it is an invasion of a persons privacy. They are questioning what you do in your own time. If you come to work, on time, and have a perfect attendance record as well as no mistakes at work, what does it matter to the employer how you spend your time away from work. You could say that the employer is forcing their moral and ethical ideals on you, even in your private life.
Until the drug testing evolves into a system that is radically more accurate and can give you a precise amount of the substance in your body as well as WHEN the substance was introduced you are being punished for what you choose as recreation. While most of the recreational substances that are in question here are illegal, that is not the question that we are discussing. That is an easy way to divert attention from the real question.
So the answer to this question is simple. Yes it does invade your privacy. From the employer's side it will save them money for several reasons. We need to have more accurate timetables and the problem could be solved. How hard can that really be? After all, we have put a remote control robot on the planet Mars. Why not make both the employer and the employee happy and just make the test a lot more accurate.