18 U.S.C. § 938

(a) Except as otherwise provided by law, the open carry of firearms in urban or densely populated areas is prohibited except during authorized events, including hunting, sporting events, or ceremonial parades. (1) This subsection does not apply to law enforcement officers authorized to carry firearms as part of their duties, including security personnel, while performing official tasks. (2) This subsection does not apply to private security companies and firms conducting their duties in public spaces or places of business where they are welcomed. (b) An individual who unlawfully openly carries a firearm in violation of this section is subject to a misdemeanor offense punishable by a fine of not more than $1,000, imprisonment for not more than 6 days, or both.