Well, depending on context,…
Well, depending on context, it may be best just to say “copyright restrictions” or “patent restrictions.”
If you need to tag the phenomenon as a whole, though, I’m keen on “intellectual monopoly,” or “intellectual protectionism”. If I’m describing the monopolists themselves or the monopoly-pushers, I am especially fond of the phrase “intellectual enclosure movement.”
I demand $50 in royalties for every time you use any of these phrases!