Pokémon Go has run into trouble with government officials before. A French mayor banned the game from his town last year, while China banned all AR games last month because of their potential risks to personal and national security. Milwaukee's move isn't a full on ban, though, just an extra layer of red tape.
The Milwaukee County Parks Department tried, and failed, to hold Pokémon Go developer Niantic responsible for damages to a city park by avid gym trainers last year. Officials told the Milwaukee Journal Sentinel that county taxpayers were stuck with the bill after Pokémon players left empty beer cans, trash piles and overflowing toilets in their wake. Residents complained of traffic congestion, late-night noise and unauthorized vendors. All of the activity cost "thousands of dollars" in damage, Sheldon Wasserman, Milwaukee County Supervisor - District 3, said.
Engadget has reached out to Niantic for comment and will update this story if we get a statement.