The stats themselves do not lie that it is effective, but what's to stop them from random testing everything in our lives and moving towards a police state. I'm on the fence though.
Would your opinion change if you or someone you knew were affected by a drunk driver?
What about airport/border security and random screening tests? Seems similar to me.
Before someone goes off on some rant on me, I said I am on the fence about this and playing devils advocate.
