Unfortunately, yes. Even if you're a paraplegic, and your MJ use has been proscribed by your doctor:

http://www.salon.com/2014/01/03/fired_for_legally_smoking_po...

Then again, we as engineers have just as much freedom not to work for companies like the Dish Network, which pulled off this particular act of callous disregard for the suffering of one of its finest employees.

Many people have gotten fired by saying something politically incorrect on Twitter or Facebook. When free speech is called into question, the standard response is that it's not protected because a company is not the government and can do as they please.

This is the other side of it. Based on this same thinking, a company can also fire you if they don't think your marijuana usage looks good for their image.

if it wouldn't be legal there's plenty of other assorted reasons you can put to an contract termination which are very broad/general and usually very hard to get around. I live in the netherlands, here 's legal , but still people usually just keep it a secret from their employers. i generally don't, but this does affect how my work and my attitude is judged by others. any miss or fail is generally blamed on pot, while if i wouldn't tell them, it will just be blamed on something else... ^^ if you intent to keep smoking weed, just accept that a lot of people (employers) will think that it makes you less fit mentally and physically for work, and they will use it as a blanket excuse for everything they want to critisize you for. just show them your care face, work hard, and prove to them they are ill informed. :)