On April 4th, 1967 (one year to the day before his assassination) Martin Luther King Jr. gave his "Beyond Vietnam" speech. It was a speech against the use of the underprivileged and undereducated in the Vietnam war. He argued that young black men were being sent to die in Vietnam for liberties that they themselves did not have in the US.
In that speech, he famously said, "There comes a time when silence is betrayal."
Stand up for what you know is right and true.