Background Pony #B0C7

Ordinarily I'd say it's still a little rude to do that without permission, but this goes further and appears to be a direct pop at John Joseco (note the title — "In the Celebrity Court of King Brony", and the three page "you're no better than us" screed that accompanies it). Calling a guy an egotistical dick and then illustrating your rant with a ripoff of his artwork just looks like the world's biggest case of sour grapes.