PISSI is not alone in burning people to death; the missiles from US drones do the same thing. So do the phosphorus and napalm bombs that the US used in Iraq. But nobody publishes videos of that.

The reason PISSI was able to publish a video is that PISSI intentionally murdered a prisoner. That is a significant step up in barbarity compared with US missiles, which are at least intended to be fired at enemies on the loose, even though they often kill the innocent.