A New York judge delivered a major blow to Mayor Zohran Mamdani’s administration Monday, halting implementation of a controversial luxury home tax after the city publicly exposed personal information of over 900,000 homeowners without proper legal justification.

Court Orders Emergency Halt to Tax Rollout

Judge Wayne Ozzi issued a temporary restraining order stopping the Mamdani administration from enforcing its planned surcharge on second homes valued above $5 million. The order prevents the city from imposing, assessing, or collecting the tax against homeowners identified on a disputed supplemental property roll. The ruling also bars enforcement of looming deadlines and prohibits further notices until the city complies with state tax law requirements for individualized determinations.

Attorney Randy Mastro, representing three New York City homeowners, blasted the administration’s handling of the tax implementation. “The city screwed this up, got it wrong. Stop the train and make them do it over,” Mastro told the court, arguing officials failed to conduct required assessments before burdening property owners.

Privacy Concerns Over Published Property List

The lawsuit centers on the city’s publication of a comprehensive list containing names, addresses, and property values of more than 900,000 New Yorkers. Mastro argued this disclosure effectively doxxed homeowners, creating public confusion and backlash. The administration sent notices forcing thousands of residents to prove their homes were primary residences, rather than first determining which properties actually qualified for the surcharge. “The city is to bear the burden. They didn’t do their homework,” Mastro argued.

One plaintiff, Simon Hedley, ultimately received an exemption after providing tax information. Mastro used this case to demonstrate how easily the city could have made required determinations itself using available data, questioning whether the approach stemmed from negligence or laziness.

Constitutional Process Questions Emerge

The lawsuit does not challenge the legality of the luxury home surcharge itself, but rather how the Mamdani administration implemented it. Plaintiffs allege the city incorrectly identified their primary residences as potentially taxable, failed to conduct statutorily required individualized determinations before mailing notices, and improperly shifted the burden of proof onto homeowners. City attorney Steven Banks defended the rollout, arguing that freezing the process would hurt taxpayers seeking exemptions and disrupt established deadlines. Outside the courthouse, Mastro declared the ruling a victory for all New York City homeowners, stating the administration sent letters to thousands who should never have been subjected to the surcharge process.