BTW, cigarettes are not even a banned substance. I agree that they have the right to ban them at the workplace....but getting into what you do off duty?....therin lies the rub.
Before you read what comes next, please let me explain that I'm not being crude to insult you, but to prove a point. Let's say that I'm an employer, and you're my employee, and I find out that you have videos on internet showing you having sex with a watermelon. There is no law preventing you from having videos of watermelon sex on the internet. I decide to fire you. Should the government regulate my decision?