New York's attorney general and Polymarket sued each other on Thursday, escalating a nationwide debate over who should regulate prediction markets and whether they violate state laws against illegal gambling, according to Reuters. The suit brought by Attorney General Letitia James in a Manhattan state court expands her push to rein in the sector, following similar cases this year against Kalshi, Coinbase Financial Markets and Gemini Titan — all accused of operating without New York State Gaming Commission licenses, encouraging problem gambling especially among those under 21, and endangering people's financial, emotional and physical health. "By running an unlicensed gambling operation, Polymarket has done more than just knowingly violate state law, they have put New Yorkers at risk," Governor Kathy Hochul said.Polymarket fought back hours later, arguing in Manhattan federal court that the federal Commodity Futures Trading Commission has exclusive authority over prediction markets. It said New York threatened irreparable harm by leaving it an "impossible choice" between obeying state regulators — undermining its federal right to operate nationwide — or continuing and facing potentially "huge" criminal liability. "This is an extraordinary assertion of state power squarely foreclosed by federal law," the company said, with Chief Legal Officer Neal Kumar saying it tried to resolve differences but state officials "preferred the media hit." New York's suit seeks civil fines, forfeiture of illegal gains and full customer restitution; Polymarket's seeks a declaration that the state cannot enforce its gambling laws against it.The case is the latest state effort against an industry that surged in popularity after outperforming pollsters in predicting Donald Trump's 2024 win over Kamala Harris, putting those states at odds with the Trump administration and the CFTC. Federal appeals courts are divided over oversight, raising the prospect the US Supreme Court may need to decide. Founded in 2020 and billing itself as the world's largest prediction market, Polymarket was out of the US market for more than three years before relaunching last December, three months after a CFTC green light. It also drew investment last year from 1789 Capital, a venture firm backed by the president's oldest son, Donald Trump Jr., who is a partner there and a Polymarket adviser; New York said the business is reportedly worth more than $20 billion. James views prediction markets as "quintessentially gambling," citing examples such as a wager on whether the Los Angeles Dodgers would beat the New York Mets by more than 1.5 runs on July 24, 2026 (the Dodgers won 4-2), and objected to Polymarket letting 18-to-20-year-olds trade despite a state minimum age of 21 for mobile sports betting.