My parents transferred me to a catholic middle school in the middle of sixth grade. The second week is was there I was called into the office. The dean then told me that it was brought to her attention by a student that I told them I was going to bring a knife to school. I of course denied it and they obviously called my parents and told them to bring me home.
Two days later, the school called and told my parents that I could come back to class and gave them a full apology. Apparently, one of the teachers had overheard a trio of my classmates (a girl and two guys) taking about how the girl lied about the knife and laughing about it.
I was welcome back and the trio was suspended. Once their parents found out about what they did, two of them transferred to other schools.