It is illegal to walk around with a snowball with the intent to throw it.

The Law Explained

Minot takes its winter mischief very seriously, classifying the act of carrying a snowball with malicious intent as a public nuisance. This ordinance was likely drafted to prevent roving gangs of youths from pelting passing cars, storefronts, or unsuspecting pedestrians. If you are packing a snowball in Minot, you better have a designated, willing target in a private yard.