Freight car graffiti - art or anarchy?

OK, even I’m not quite sure how I really feel about the graffiti that appears on the rolling stock in nearly every freight train riding the rails. Nevertheless, it’s a part of the modern railroad scene that I’m compelled to model. In this case, I’ve got a friend, who has a friend, who knows an “urban artist.” I’ve asked this artist to create some authentic art on both sides of my MTH no. 20-90046 CP Rail 100-ton cylindrical hopper. Turns out I liked it enough to commission another car. Meanwhile, I’m trying my hand at tagging with a Sharpie marker and applying decals to various dark corners of my layout. Conversely, I’ve already painted over some of the graffiti I added!