I would agree to this except for that pesky little right I have as an employer to hire whomever I choose. I did not come to your house and force you to work for my company. That's like saying that just because little Jimmy is dumb as hell he ought to still be accepted to Harvard. What about little Jimmy's right to a quality education?
You do not have the right to ask your candidates if they are married, what are their sexual practices, if they have kids, their religion and so on. Those are considered intrusive, a pee in the bottle test is as intrusive as asking me if I have any "weird sexual practices".
What happens on my time, happens on my time, it's none of the employer's business as long as both do not interfere.
You gave him the right to intrude when you took the job, knowing full well that there would be random drug testing. Just as I forfeited the right to drive with an alcohol content of more than .04 when I got my CDL. Or any other of the things I agreed to WHEN I TOOK THE JOB.
One does not forfeits his rights when he takes a job. It doesn't work that way! You can't come to my home, break-in and go take a shower in my bathroom before checking the content of my dresser just because you're my employer.
The only part I can agree with you is that the guy who took the job agreed to the pee test. But that's not the issue I'm discussing here, the idea I'm defending is that such test should not be legal unless there's suspicions as they are intrusive.