Nope.
Invasion of personal privacy, bottom line. It's no business of anyone's what I put in my body. Regardless of the reason you might have to check.
Doesn't matter anyway, there are ways around such tests (case in point, Lance Armstrong)....so it just becomes a waste of money.
Where there's a will, there is a way. I'm more interested in finding these people jobs and HELPING them out, regardless of what they do in there personal lives. If they can't hold a job after being trained by the system, sorry you are cut off. IMHO.