Actually did something similar in high school by accident. Me and some nerd friends built a To Do list app. The school was really supportive and thought it was cool, so they emailed it out to everybody. Well guess what, we stored passwords in plaintext as that’s how we were tsught to do it. And guess what, students, when creating an account based on a school email, use the same password as the school email. Most social media was blocked, so school email was how people were communicating with school friends back then. We suddenly had access to most people’s personal conversations.