The answer is addressed free speech and student's rights.
The movement was called Free Speech Movement (FSM), the movement began in 1964, when students at the University of California, Berkeley protested a ban on on-campus political activities. The protest was led by several students, who also demanded their right to free speech and academic freedom. The phenomenon of the movement was inspired first by the struggle for civil rights and later fueled by opposition to the Vietnam War.
At the time, North and South Korea were just known as Korea, so it's neither of those two. I'd probably guess Hungary since it's closer to Germany than Greece is, but I'm not 100% sure.
