Can't a Blu-ray's playback be disabled by revoking the AACS cert (or whatever key) the blue-ray uses for DRM in the blu-ray players? Especially since they're all always connected now.
For anyone else wondering, this seems like a good explanation:
Yes, some discs have something that does something with the network, but I can't imagine it's worthwhile (but maybe if I knew what it was, it could be?)
One of my blu-ray players had a bunch of streaming clients, but they pretty much all expired.
It might be nice if you could use a blu-ray player to play discs copied to your network, but I think DRM makes that a no, and anyway, 4k blu-ray can exceed 100mbps at peaks, and I don't think 1g ethernet has made it to 4k blu-ray players yet. But it has for some models of Apple TV, and some android TV products, including the well regarded Nvidia Shield.