Hundreds of graduates at Harvard University walked out of their commencement Thursday after the school announced 13 students who participated in the recent pro-Palestinian protests on campus would not be allowed to receive their diplomas with fellow students. Groups of graduates walked out chanting “Free, Free Palestine” and “Let them walk, let them walk” in reference to the students barred from walking at the ceremony, The Associated Press reported. A total of more than 1,000 students participated in the walkout, according to the school’s protest groups.