A group of activists held a protest on Monday, April 25 during a lecture in Chicago entitled, “Turks and Armenians: Nationalism and Conflict in the Ottoman Empire,” which featured genocide denier Justin McCarthy, The Armenian Weekly reports.

Prior to the start of the lecture, members of the University of Chicago Armenian Students Association (ASA), together with Students for Justice in Palestine, the UChicago Hellenic Students Association, and the Armenian Youth Federation (AYF), handed out flyers to attendees condemning the event.

At the beginning of McCarthy’s talk, protesters placed red tape over their mouths, held up banners, and conducted a silent protest by standing in unison and turning their backs to the lecturer. They then staged a mass walk-out in protest of McCarthy’s denial of the Armenian Genocide.

“The University of Chicago has a long history of protecting the right to free speech. But in the case of the Armenian Genocide, the historical facts are clear and genocide denial should not be tolerated by any degree,” Daron Bedian, a member of the UChicago ASA, told the Armenian Weekly.

According to Bedian, while several groups—including the Armenian National Committee of Illinois (ANC-IL)—sent e-mails to the university urging that the event be canceled, McCarthy’s talk was allowed to take place.

Bedian said that the university surely would not allow a neo-Nazi to spread Holocaust denial on campus, and that “the university must then explain allowing an Armenian Genocide denier to speak.”