The Justice Department has filed an antitrust lawsuit against real estate software company RealPage, accusing it of an illegal scheme that allows landlords to coordinate to hike rental prices. The lawsuit accuses the company of violating antitrust laws through its algorithm that landlords use to get recommended rental prices for apartments. Justice Department officials say the algorithm allows landlords to align their prices and avoid competition that would keep rents down. In a statement, RealPage said the Justice Department’s claims were “devoid of merit and will do nothing to make housing more affordable.”