I have an admission to make. When I was an undergraduate, I bought a lot of notes. And I did far better in the courses in which I did.
The process was easy. Show up to class the first week to get the syllabus. See if the university library or any other local libraries had the texts, even if they were a different edition. If not, wait until the first exam. A week before the first exam, buy the notes, buy the text, and fill in the purchased notes with facts from the text. Take the exam. Return the books. Repeat for finals.
Did I do this for all my courses? No. If the professor was especially engaging, or the course involved some level of participation, I showed up with some degree of regularity. But for giant sophomore biology courses or economics courses, going to class was a waste of time. I could buy two or three weeks of notes for the equivalent of an hour’s worth of work as a tutor. And I probably learned more teaching than I did studying. In fact, I probably learned less than students who showed up every day, but not enough less to make it worth my time.
And so, we come to the case of a professor suing a company offering notes from his course. I am actually fairly sympathetic to the guy. Writing a good lecture takes time, and often involves a lot of creative expression in organizing the material. On the other hand, the notes are not the lecture–and if they are, he probably isn’t very good as a lecturer.
The solution, in any case, seems simple enough: publish your notes yourself, and charge less than the competition.