In a letter sent on Monday to Facebook CEO Mark Zuckerberg, twenty-nine civil rights groups call on him and COO Sheryl Sandberg to step down, citing years of the company's role in "generating bigotry and hatred towards vulnerable communities." The rights groups urge the company to restructure the board to improve accountability of senior leadership going forward. The letter says Facebook leaders are "unable to adequately address the valid concerns of the civil rights community" and that it's time "for significant changes in, not only your policies, but also your leadership structure."