Modify your own car

You may own your car, but you don’t own the software that makes it work— that still belongs to your car’s manufacturer. You’re allowed to use the software, but in the past, trying to alter it in any way (including fixing it by yourself when it breaks or patching security holes) was a form of copyright infringement. iFixit, Repair.org, the Electronic Frontier Foundation (EFF), and many others think this is ridiculous, and they’ve been lobbying the government to try to change things.

The legal and technical distinction between physical ownership and digital ownership is perhaps most familiar in the context of DVD movies. You can go to the store and buy a DVD, and when you do, you own that DVD. You don’t, however, own the movie that comes on it: Instead, it’s more like you own limited rights to watch the movie, which is a very different thing. If the DVD is protected by Digital Rights Management (DRM) software, the Digital Millennium Copyright Act (DMCA) says that you are not allowed to circumvent that software, even if you’re just trying to watch the movie on a different device, change the region restriction so that you can watch it in a different country, or do any number of other things that it really seems like you should be able to do with a piece of media that you paid 20 bucks for.

Cars work in a similar way. You own the car as a physical object, but you only have limited rights to the software that controls it, because the car's manufacturer holds the copyright on that software. This prevents you from making changes to the software, even if those changes are to fix problems or counter obsolescence, as well as preventing you from investigating the security of the software, which can have very serious and direct consequences for you as the owner and driver. It’s also worth pointing out that (especially in older vehicles like the 1995 Volvo 940 Turbo belonging to a certain anonymous journalist) relatively simple computerized parts can cost a ridiculous amount of money to replace because there is no legal alternative besides buying a new one from the manufacturer, who hasn't made them in 20 years and would much rather you just bought an entirely new car anyway.