Human social psychology, aka. "The wisdom of crowds, and the stupidity of herds" (1), in which the average opinion of large groups of people is closer to the truth, than each individual opinion. By informing all individuals of the propaganda you wish to spread, you can influence that average, hijack, and change it to the stupidity of the herd aka. Gleichschaltung (2), which is why these people want to decide what is and what isn't "dangerous" speech. Fuck'em.
