Under Pruitt, Oklahoma sued the EPA and lost on challenges to the EPA's regulatory authority over mercury and other toxins, as well as pollutants responsible for creating regional atmospheric haze. It challenged the manner in which EPA sued unrelated entities and for what Pruitt termed the agency's "sue and settle" practices. Oklahoma further sued and lost after the EPA declined to provide extensive records in a FOIA lawsuit, a request the federal judge hearing the case found to be overly broad and economically burdensome.