It is proper Netiquette to refrain from depicting or watching human violence. Don't watch graphic violence.
Violence it is uncivilized. Violence begets violence. This means that violent media makes people act violently because media is consumed by people. It is taken in. Violent video consumption goes against society. Netiquette is civilization. They are opposites.
Promoting peaceful videos and and cartoon violence creates a psychological barrier between human violence and make believe. Many people support non-violent content because studies have shown a direct connection between violent media and aggressive behavior.
Use moderation when uploading or watching human violence because it teaches it.