A group of Chinese citizens who live in Florida and a real-estate brokerage firm that caters to Chinese-speaking people on Monday filed a federal lawsuit challenging a new state law aimed at restricting the sale of properties to people and businesses linked to the Chinese government. The law (SB 264) prohibits Chinese citizens from buying farmland or any property within 10 miles of a military installation or “critical infrastructure,” such as a seaport or airport. The lawsuit, filed in the Northern District of Florida, said the law “will have the net effect of creating ‘Chinese exclusion zones’ that will cover immense portions of Florida.”