Concept: shinobi are meant to be stealth masters and everything, but in reality, they're huge gossips.
So the rumor mill has been cranking on Kakashi Hatake the Copy Ninja for a long time, and there's a conspiracy theory going around (and gaining steam) that the "Copy" is tongue-in-cheek, owing to Kakashi actually being no person at all.
"Guys, did you hear? We have a new Kakashi-senpai."
"Last month, plebeian. Get up to date."
"I swear, I saw his eyes last week, and he had more wrinkles around them.
"But the pants fit him the same!"
"No, no, the crotch area is way tighter than it used to be. It's definitely a successor."
"He was totally mackin' on Guy-senpai last year, and now he's running for the hills as soon as he sees him!"
"But this one's hotter, though."
Kakashi is not a man. He is a myth, he is a symbol. He's the hero they deserve, but not the one they need right now. Under that mask, he's a silent guardian, a watchful protector.
The symbol of the dark. He is vengeance. He is the night.
(And they've all agreed to read terrible porn for consistency of their cover identities.)