Hey dude, I love your wallpapers. I have Lycan! as my background. While surfing youtube I saw this dude called "Boxofbeer Channel" use that exact wallpaper for commercial use as the thumbnail of his videos where he generates income via ads.If he doesnt answer you, you can use the video feature "more" -> "report" -> "infringes my right" to temporarily close his channel until he reacts.