EFF DEF CON T-Shirt Puzzle

Every year, The Electronic Frontier Foundation creates a unique limited edition T-Shirt for DEF CON. Since at least DEF CON 21 in 2013, these shirts have included a hidden puzzle (I don’t know if the shirts existed before that). I’ve solved all of them that I know of, and I feel like it’s time I started doing write ups for them:

• 2024: XI Justice