The federal government wants to be clear with its federal employees that might live in states that have reformed their marijuana laws: Marijuana remains illegal, so don't use it. In guidance issued this week from Katherine Archuleta, director of the U.S. Office of Personnel Management, to the heads of all federal departments and agencies, Archuleta says in no uncertain terms that marijuana use for the more than 4.1 million federal employees across the nation is banned. "Federal law on marijuana remains unchanged," Archuleta writes in a letter announcing the guidance.