The question of copyright infringement in Pharell Williams’s and Robin Thicke’s song “Blurred Lines” has been raised again, following an appeal that the pair filed this Monday against the March decision that ruled against the use of Marvin Gaye’s “Got to Give It Up” in the song’s instrumentals. Vulture presented a breakdown of the reasons why some people have been outraged by the decision, and why it can be argued that what some call an “homage” in fact constitutes illegal appropriation.