I don't think that employees should be fired for off the job medical marijuana use. I mean its only for medical use that person is using it for. I pretty sure that everyone choose other medical ways that are possible before using marijuana use. And marijuana does cure some serious health problems
Personally, I terminating employees for outside marijuana use is not necessary. As long as the employee never comes to work while under the influence nor their use outside of the job affects it while they are on the clock, I really don't see it being a huge issue. There are so many worse things out there a person can be doing besides Marijuana.