Lexmark has spent nearly 20 years fighting the war on carbon, trying to stop you from refilling your laser printer cartridges. In 2003, they attempted to use the DMCA and DRM to argue that it was an act of piracy (the courts didn't buy it) and then in 2015, they went all the way to the Supreme Court with the idea that you were violating their patent license terms if you treated the cartridges you purchased as though you owned them.
Today, the Supreme Court told Lexmark it was wrong. Again. Saying that when a patent holder "chooses to sell an item, that product is no longer within the limits of the monopoly and instead becomes the private individual property of the purchaser, with the rights and benefits that come along with ownership."
Lexmark was trying to use patents to get something that DRM didn't get them back in the naughties, but they might well take another run at it. Back then, the company lost in part because the very simple software in its printer cartridges (a 12-byte program!) didn't rise to the level of a copyrightable work. Today, a cartridge might have tens of thousands of lines of code in it -- and thanks to dreadful laws like Section 1201 of the DMCA, all Lexmark would have to do is design their cartridges so that refilling them required breaking some kind of DRM, and they'd be able to threaten their competitors with $500,000 fines and 5 year prison sentences (for a first offense) if they helped you refill your cartridge.
The Court also rejected the argument, raised perennially by rightsholders, that they are entitled to profit via the business model of their choosing, even if that business model requires an expansive reading of the patent or copyright monopoly they enjoy. This argument arises in many contexts. For example, we've seen video game console makers argue that your traditional rights to modify your gaming console must be restricted to enable the loss-leader business model of selling inexpensive consoles and pricey games. Makers of Internet-of-Things devices often require a subscription to function. And manufacturers often try to place restrictions on reselling digital goods, repair markets, and other uses that the law has traditionally allowed customers to engage in. A rightsholder may be able to make more money if you have to pay to exercise your existing rights, but ownership of a patent or copyright should not be a hunting license that allows an owner to control and destroy any business that threatens their profits. Today, the Supreme Court reaffirmed that a patent does not confer unfettered control of consumer goods to the patent owner.