(Denver, CO)  --  Employers in Colorado can fire their workers for off-duty medical marijuana use, even though it's legal in the state.  The "Denver Post" reports a court of appeals is upholding the termination of a man for using medical marijuana on his own time.  The ruling sets a precedent that could prevent states from providing workplace protections for medical marijuana users.  The court decided that since marijuana is illegal under federal law, employees are not protected for state-licensed use.