Straight: Bob listens to ICP, has posters of them in his room, and always has Faygo in the fridge.
Bob does all of the above, answers the phone with "Whoop, whoop!", listens only to ICP (and when he's forced to listen to something else, compares it unfavorably to ICP), wears the Monster Clown makeup everywhere he goes (even to work or school), and drinks only Faygo. He's a Straw Fan, in other words.
Bob listens to ICP once in awhile, but not that often.
Bob wears Monster Clown makeup and drinks Faygo, but turns out to have never heard of ICP.
Double Subverted: He starts listening to the group more and more, and becomes an integral part of the Fandom.
Zig Zagged: ???
Bob does not listen to ICP.
Bob has never heard of ICP.
The setting is After the End, or waaaaay before ICP even existed, or in a remote and rural area.
Bob simply does not like ICP. (Whether it's a mild dislike or outright hatred.)
Bob is a Visual Kei fan, not an ICP fan (his makeup is more inspired by SEIKIMA-II and Golden Bomber) and most definitely not a Juggalo. Confusing him for one is such a Berserk Button that he will actively rant about the difference.