Facebook and Twitter are facing renewed calls from US lawmakers to ensure ads on their respective platforms aren't used to spread hate. The two firms are currently cooperating with Congressional investigators looking into Russian meddling in the 2016 election. And now, black Congress members are urging them to probe new ads, and make leadership changes. In a letter obtained by Recode, Reps. Robin Kelly, Bonnie Watson Coleman, and Emanuel Cleaver further press the companies to clamp down on ads "aimed at inciting racial discontent" or "voter suppression." They also suggest the companies appoint people of color to their boards of directors, and conduct new audits of targeted advertisements.