Video can convince people to kill each other now because it is assumed to show real things. Show people a Jew killing a Palestinian, and that will rile up the Muslims, or vice versa.
When a significant fraction of video is generated content spat out by a bored teenager on 4chan, then people will stop trusting it, and hence it will no longer have the power to convince people to kill.
When a significant fraction of video is generated content spat out by a bored teenager on 4chan, then people will stop trusting it, and hence it will no longer have the power to convince people to kill.