Millions of rents across the country may now be set using one company’s algorithmic software, according to a federal lawsuit and a Washington Post analysis.

The lawsuit arrives as U.S. renters continue to struggle under a merciless housing market, with incomes failing to keep up with rent increases.

The U.S. Department of Justice is suing several major landlords for allegedly colluding to keep rents high. The lawsuit accuses them of using an algorithm to set rents and sharing sensitive pricing information to avoid competition.