I read this news article
https://fox6now.com/2019/12/02/city-ordinance-bans-snowballs-in-wausau-in-the-interest-of-public-safety/
and had two takeaways.
The first one is the ordinance applies only to public property. Banning activity on public property isn't all that rare. Drinking alcohol, smoking, noise, etc, are banned or restricted in communities all over the country on public property. If I read the article correctly, if you want to have a snowball fight in your own backyard, have at it.
The second takeaway has to do with enforcement. The police noted that not one citation has been issued. That's the problem I have with ordinances like this one. What's the point if it is not going to be applied fairly and equally? It's just stupid, feel good politics. Kind of like plastic bag bans or fees for their use (recently passed in my town). Doing "something" about plastic bags really isn't going to impact the total use of plastic, but by Gawd, it did raise awareness for about 5 minutes.