Poop6 is the result of a failed attempt to write the word "people" on a classroom whiteboard.
Typically, when a student is called upon to write his answer to a question in class on the board, he pays careful attention to how he spells words. In this certain case, said student did not consider the spelling or appropriateness of his response. As a result, the word "people" was transformed into "poop6", for the entire world to see.
Immediately following the realization that a fellow classmate wrote "poop6" on the whiteboard, ridicule and hysteria from the students ensued.
Poop6 will now be forever remembered as an alternative way to spell “people”.
Dan-"Hey Tim, did Karl just write poop6 on the board?"
Tim-"I think he did. What does that even mean?"