Legally speaking, how is that you profit from selling class notes to a class I teach?

Legally speaking, how is that you profit from selling class notes to a class I teach? It would seemed that intellectual property rights are at stake, given that these notes derive from my class. More importantly, it is services like yours that are responsible for the watering-down of the American education system. Students would rather pay you a fee than actually take notes themselves. I don't give a damn if Business Week has written about you.