A few of my close friends know this story, but most people who know me would be appalled to hear it haha.

I was a punk rocker kid in high school with a lot of hate to give the world. There was this newcomer to the punk rock group at school named Joe. Joe was a flunky and 3 years older than us (seniors), and was just the dumbest, dirtiest asshole you ever did see. I can't think of a single positive thing to say about him. Anyway, Joe is a student assistant in the counseling office along with my good friend Conor, who also hates Joe. The student assistants deliver summons to teachers to send their students to the counseling office. Conor acquired a whole stack of blank summons and would routinely forge them to summon whatever friend he felt like to roam the halls with him. One day Conor enters my English class, hands my teacher a note and I am told to report to the counseling office. Once outside, he informs me that today is the day we are going to get Joe good, he just doesn't know what we're gonna do yet. We get to the counseling office and I see Joe's backpack under a table where he left it to go run notes around. I heard a little voice in my head say, "Man it'd be a shame if someone took a massive shit in that backpack and then put it right back where it was." Without thinking twice, I grabbed the backpack, casually walked off to the bathroom and deposited about 3lbs of shit into the main pocket then put it right back under the table. Being the scholar that Joe was, he apparently didn't open his backpack for the rest of the day and a few hours later I see him walking down the hallway accusing everyone around him of farting as he carries my shit around on his back. I fucking lost it and started cracking up, at which point I decided it would be best to leave the school. He found out and chased me to my car and threw a clay head at me, but it was totally worth it. I was never formally punished by the school for it. I think it was a combination of them not having enough evidence and not wanting it to become news. TL;DR: I took a shit in a kid's backpack at my high school and he wore it around for half a day