This is a fun story, detailing the hack a group of high school students perpetrated against an Illinois school district, hacking 500 screens across a bunch of schools.

During the process, the group broke into the school’s IT systems; repurposed software used to monitor students’ computers; discovered a new vulnerability (and reported it); wrote their own scripts; secretly tested their system at night; and managed to avoid detection in the school’s network. Many of the techniques were not sophisticated, but they were pretty much all illegal.

It has a happy ending: no one was prosecuted.

A spokesperson for the D214 school district tells WIRED they can confirm the events in Duong’s blog post happened. They say the district does not condone hacking and the “incident highlights the importance of the extensive cybersecurity learning opportunities the District offers to students.”

“The District views this incident as a penetration test, and the students involved presented the data in a professional manner,” the spokesperson says, adding that its tech team has made changes to avoid anything similar happening again in the future.

The school also invited the students to a debrief, asking them to explain what they had done. “We were kind of scared at the idea of doing the debrief because we have to join a Zoom call, potentially with personally identifiable information,” Duong says. Eventually, he decided to use his real name, while other members created anonymous accounts. During the call, Duong says, they talked through the hack and he provided more details on ways the school could secure its system.

EDITED TO ADD (9/13): Here’s Minh Duong’s Defcon slides. You can see the table of contents of their report on page 59, and the school’s response on page 60.