So, if you bought a DVD licensed by Sony, can they now legally enter your house and take your DVD?
Or can Sony have some sort of DRM that prevents the DVD from playing when Sony loses the license agreement?
I’m just trying to reconcile how digital purchases can be subject to license terms changes, while a DVD apparently can’t be.
This isn’t entirely true and more so for Blu-ray disks. You own the physical media along with a temporary, limited license to watch the film on the media. That license is revocable and, technically, can be removed in the case of the publisher no longer being authorized to distribute licenses. It hasn’t really happened yet but Blu-ray players, as part of the spec, can connect to the internet to verify their licenses. If they wanted to, Sony could make your Blu-ray disks worthless if all your players follow the spec correctly. If you have a standalone drive or a drive hooked up to a computer that doesn’t fully follow the spec, you can copy the film from the media but you’d be breaking the law in most places for exactly the reason you’ve stated - breaking the encryption is illegal.
So there is a “license” with a DVD. It’s just far less enforceable than it is on a system where there’s no physical portion of the media for them to take away.
That’s true, blu rays came with updatable firmware that you had to keep nice and happy or they’d stop playing. Like one other commenter said - you own the disc, and the bytes on them. If it’s playable is a whole other story