Continued Weed
These test may be unreliable. Also, because weed stays in your system long, users are encouraged to turn to harder drugs, which can be out of your system in 2 days (weed may be detected up to 28 days).
The U.S has a list of Controlled Substances and lists weed with all hard drugs.
So in essence if you are tested, It does not matter whether you use weed of Heroin, you failed the drug test. This can have some very unpleasant consequences for the ones failing. And what is the test was flawed?
Yet you can be a raging alcoholic and that does not matter.
Canada's position, I believe is that present impairment is what matters, not your history that you smoked the evil weed. And in Canada, it is a violation of privacy rights I believe to do tests, unless your work takes you into the U.S.
Personnally, the insistance of a test proved very hard on me... I refused the test, but was forced to give up a position I enjoyed. Even though it was only occasional.
I was also floored by the amount of "detox kits" available in the US flushing you out so you can pass tests. Who knows how healthy this can be.
As long as weed is done responsibly, and in moderation (as with anything), it can prove to be beneficial. It has helped me with a medical condition.. and I am going to approach my doctor for an actual prescription.
We are lucky we live in Canada.