After reading this article, I got to thinking about how I started in my job as a teacher. I worked as a teacher, doing all of the duties of a teacher for an entire semester. Not only was I not paid, but I had to pay full college tuition for the privilege. This experience made it possible for me to then go on and become a teacher. The college calls it "student teaching". It is really an internship. I had to work several other jobs at the same time to make money.
This would be no different than if I had become an intern at a lab or a business. Internships are not jobs. They are a learning experience. This article makes me curious if student teaching will fall under this law. The school did benefit from having me there: I really did teach.