Pressure is mounting on Facebook to take responsibility for its white supremacist problem. In the wake of a host of major advertisers stepping away from the platform, three U.S. Senators have sent a letter to Facebook asking why it can’t seem to clean up its act and enforce its own rules.

U.S. Senators Mark R. Warner (D-VA), Mazie K. Hirono (D-HI), and Bob Menendez (D-NJ) signed the letter, which calls out Facebook for publicly aligning itself with the Black Lives Matter movement while profiting from white supremacist content on its platform. “Its failure to address the hate spreading on its platform reveals significant gaps between Facebook’s professed commitment to racial justice and the company’s actions and business interests,” the Senators said.

The Senators cited several studies and public interviews that explained how Facebook continues to be a platform for violent extremism. A recent Wall Street Journal expose detailed how senior Facebook executives “shut down efforts to reform the platform’s tendency to amplify hyperpolarized and extremist content after Vice President of Global Public Policy Joel Kaplan deemed the efforts ‘paternalistic,’” according to the Senators.

The letter cites Facebook’s own community standards which explicitly state it does not allow hate speech on its site. In a clarification post from 2019, Facebook explicitly stated that it considered white supremacy hate speech. “The prevalence of white supremacist and other extremist content on Facebook—and the ways in which these groups have been able to use the platform as organizing infrastructure—is unacceptable,” the Senators said.

The Senators called out the “boogaloo movement” by name and cited the case of U.S. Air Force sergeant Steven Carrillo. Carillo has been indicted for the murder of a federal agent after firing an assault rifle from the back of a moving car. According to authorities prosecuting the case, Carillo met his getaway driver on Facebook and expressed his desire to commit violence on the platform.

“In light of these clear policies—and others against ‘Violence and Incitement’ and ‘Dangerous Individuals and Organizations’—we are concerned Facebook is unable (or unwilling) to enforce its own Community Standards and rid itself of white supremacist and other extremist content,” the Senators said.

The letter comes as Facebook is dealing with mounting pressure from advertisers to clean up its platform. On June 26, Unilever—one of the world’s biggest advertisers and the owner of Dove soap—announced it would pull its ads from Facebook as part of the Stop Hate For Profit campaign. Coca-Cola announced a 30 day freeze on social media ad buys, and dozens of other companies big and small are joining the cause.