A cabinet secretary, President Trump's niece and an Oscar-nominated director have emerged as potential targets of Mayor Zohran Mamdani's new tax on luxury second homes.

Mamdani's administration fired a warning shot last week when it published an online list of property owners who might be subject to the surcharge on luxury second homes. The list includes owners' names, addresses and market value of properties.

The release of the list threatens to stir up existing tensions between the mayor and the city's elite. The city has also begun sending out notifications to homeowners that they might be subject to the new tax. "If you have a second home in New York City worth more than $5M, check your mailbox when you're back in the five boroughs -- because you've got mail," the mayor said in a post on social media.

Steven Fulop, president and chief executive of Partnership for New York City, a prominent business group, said the list seemed like a tool to target and shame certain individuals.

"Publishing a list of individual taxpayers' names alongside a policy designed to raise revenue from them sends an implicit message that these are people who've done something wrong, rather than simply people the city has chosen to tax more," Fulop said. "The mayor has already won the election -- he doesn't need to govern by singling people out to make a political point."

The new surcharge, which went into effect July 1, targets second homes worth $5 million or more. It can easily add tens of thousands of dollars to some homeowners' city tax bills. A Finance Department spokesman said the list was released as per state law and will be used to identify owners subject to the tax. It includes the type of information that real-estate lawyers say has long been publicly available.

The list includes a $37 million property of which Commerce Secretary Howard Lutnick is the trustee. A property owned by Trump's niece, Mary Trump, is listed as being potentially subject to the tax. Also listed are more than a dozen units at Trump Park Avenue, a luxury condo building where Ivanka Trump and Jared Kushner, and the president's former lawyer, Michael Cohen, have lived.

The list also includes a nearly $76 million townhouse on Manhattan's Upper East Side owned by the ex-wife of billionaire financier John Paulson and a property owned by filmmaker Darren Aronofsky.

None of these named individuals could be reached for comment.

The newly released list is preliminary and encompasses roughly 960,000 properties out of a total of about 3.7 million units in the city. That is far more than officials expect will ultimately be subject to the pied-à-terre surcharge. New York Gov. Kathy Hochul's office previously estimated the tax would apply to roughly 10,000 second homes.

The state legislature approved the pied-à-terre tax earlier this year at the urging of Mamdani, a Democratic socialist who won office campaigning on an ambitious affordability agenda that he wants to fund through increased taxes on the wealthy. As mayor, he pushed state lawmakers to raise billions of dollars by raising tax rates on high-income earners and major corporations. Hochul balked at those taxes but backed the pied-à-terre tax, which her office estimates will raise at least $500 million a year in revenue for the city.

In May, Mamdani celebrated the planned pied-à-terre tax with a social media video set outside of billionaire Ken Griffin's penthouse on Central Park South, one of the luxury properties that he said would be subject to the levy.

"This pied-à-terre tax is specifically designed for the richest of the rich," Mamdani said in the video. Under the new surcharge, Griffin could end up owing $1 million a year, on top of the $837,000 in property tax he pays now.

The Finance Department is expected to pare down and fine-tune the list. The city intends to notify individual homeowners of their pied-à-terre tax bills by Aug. 30, and homeowners can appeal the decision. The list is scheduled to be finalized in December.

The city typically publishes an annual tax roll of all property owners, and real-estate attorneys say the information included is par for the course.

"It's not doxxing because it's all the same information that's on the regular roll," said Adrian Diaz, a property-tax attorney at Hogan Lovells Cadwalader.

Diaz noted that the mere size of the list is enough to alarm homeowners who might find their names, despite not ultimately being subject to the tax. He has been fielding calls from his own worried clients since the list was released.

"A shorter list, something more targeted would have been more appropriate," he said.