The U.S. Department of Justice has filed a federal lawsuit against the City of Milwaukee to strike down a city ordinance that bans masks and requires federal officers to display identifying information, arguing it unconstitutionally regulates the federal government and jeopardizes officer safety. The ordinance, enacted by the Milwaukee Common Council, targets immigration enforcement actions and imposes fines for noncompliance while demanding visible agency affiliation and name or badge numbers. Milwaukee officials defend the measure as a public safety tool, while federal authorities contend that local control cannot override federal operations and that the rule undermines operational flexibility for federal agents. The lawsuit names the mayor, city attorney, and police chief alongside the city and seeks a declaration that the ordinance is unconstitutional under the Supremacy Clause. Federal officials warn that restricting face coverings and identifiers could hinder federal law enforcement and strain cooperation with local authorities. This dispute is being pursued across multiple filings and statements from DOJ representatives and Milwaukee officials.