Last summer, Pokémon Go players descended on Milwaukee County parks in droves, and those Poké masters allegedly left quite a mess. This has prompted a response from the people in charge of those public spaces.

The Milwaukee county board passed an ordinance last week that will require Pokémon Go developer Niantic to acquire a permit to use the county’s park locations in the location-based monster-catching simulator, according to the Milwaukee Journal Sentinel. The board enacted this new rule in response to claims that Pokémon Go players caused thousands of dollars in damage to area parks that the county had to pay for itself. This rule won’t affect players because the Milwaukee board is only interested in targeting the company responsible for creating the game.

I’ve reached out to the Milwaukee county board and Niantic to ask about this ordinance, and we’ll update this story with any new information.

But this is a rule that Niantic probably doesn’t want to abide by because the Milwaukee board is potentially violating the developer’s First Amendment right to free expression.

“[Cities and public officials] don’t have an option to file suit against Niantic. That’s not really in the cards,” Avvo chief legal officer Josh King explained to GamesBeat last summer. “If you want to look at the pure legal issue there, Niantic or Pokémon can associate any piece of property with, let’s call it a virtual signal. They’re well within their First Amendment rights to do that.”

Put simply, this ordinance is essentially saying that Niantic’s software cannot use Milwaukee’s parks, and that doesn’t seem all that different than if the board tried to pass a rule prohibiting artists from referencing the county’s parks on television, in books, or on a map. To get the ordinance overturned, Niantic or another interested party would potentially have to file a lawsuit, and nothing like that has happened yet.