That ad is for an internship, not a hackathon. It offers room, board and $3333/month. That's a better offer than most summer jobs for college students and more

That ad is for an internship, not a hackathon. It offers room, board and $3333/month. That's a better offer than most summer jobs for college students and more money than most students would make freelancing. Unpaid internships are still disturbingly common. The ad makes it clear that real work is expected. I really don't see a problem here.