There's no mention of equity for people applying as "Hackers". That position is a whole lot less meaningful (financially and otherwise) if you're not a stakeholder.
"You will be working your butt off for very little money, and there is no guarantee that even if you are a great programmer that the company you are working with will succeed, or that if it does that there will be a long-term opportunity for you."
However, I do think that its definitely a great opportunity for a student who is looking for a more than usual summer internship.