Colorado Attorney General Phil Weiser and federal regulators filed a joint lawsuit against the largest apartment owner in the country on Thursday, accusing it of intentionally misleading tenants about the cost of its rentals.

The complaint filed Thursday charges that the country’s largest landlord failed to include information about numerous mandatory fees in its listings.

The U.S. Federal Trade Commission has filed a lawsuit accusing property management company Greystar of swindling renters across the country out of at least $100 million using hidden fees.