Greystar, the nation's largest landlord, has agreed to a settlement with the Justice Department to stop using algorithmic rent-setting software. Federal prosecutors claim this software could violate laws against price-fixing and collusion with other landlords to raise rents. The proposed deal, which requires judicial approval, would prohibit Greystar from using anti-competitive algorithms that rely on rivals' sensitive data. Greystar was using rent-setting software from RealPage, a company previously investigated by ProPublica for potentially facilitating cartel-like behavior among landlords. The Justice Department has also sued RealPage itself. This settlement has drawn praise from both Republican and Democratic officials, who emphasize the importance of competition for affordable housing. Greystar maintains it did not admit wrongdoing and believes its use of the software was legal, citing unclear regulatory guidance. The company also reached an agreement in principle to settle a class-action lawsuit brought by renters. This development follows ProPublica's 2022 investigation and subsequent lawsuits against RealPage and several landlords, including Greystar. The Justice Department's actions signal a willingness to address collusion occurring through algorithms, which are described as the "new frontier" of antitrust violations.