The trend with so-called intellectual property is that the supposed owner has a post-sale entitlement to extort a revenue stream. Russell McOrmond put a very unusual spin on this trend, "Give a man a fish, make it illegal to teach fishing". While Russel is writing from the perspective of his observations concerning philanthropy, Russel remarks can be expanded to apply to the content industry as a whole. That is that the content providers: "... are actively involved with making a variety of "teaching" (sharing of knowledge) expensive and/or illegal."
The post by Russell McOrmond was found via TechDirt. Additionally, for added context on how so-called intellectual property is adversely affecting our educational system through outrageous monetization, see the TechDirt posts: "School Wants To Claim Copyright Over Any Lesson Plans Created By Teachers" and "Professors Claiming Copyright Over Their Lectures". Ultimately, how could students ever use the knowledge that they have been taught should that knowledge be locked behind a copyright paywall?