'Star Wars' actor John Boyega asked protesters to "take a knee" outside the Houses of Parliament during a Black Lives Matter march in central London on Wednesday (June 3).br br Boyega also led a chant of "no justice, no peace" through a megaphone.br br "Taking the knee" is a gesture of protest against racism and police brutality, which began in 2016 by American Football player Colin Kaepernick.