In theory, you could make a fake executable with the mkv file extension on a unix system, by making it a shell script with a bunch of garbage data at the end, marking it executable, and distributing it with a tarball. But the chances someone will do that is insanely low.
Also it has caveats:
It'd rely on your double clicking it, and having your file manager not warning you about it.
Video players wouldn't run the shell script code, if it'd run the file at all.
Depends on your NAS server. If you're like me and using an old optiplex, you can fit WAY more 2.5" drives in it, and they're pretty cheap. If you have an actual proper server chassis, then you probably want 3.5" NAS hard drives cuz warranty and all that.
Oh, it's worse than blocking certain wifi cards, it blocks all wifi cards except what came with the laptop. I mispoke when I called it a blacklist, it's a whitelist.
I've done it before. It's not particularly difficult, just very time consuming. And at the end, you're left with a distribution that's not really that useful without repackaging everything you did into a package manager so you can do updates without borking it.
Great as a learning tool to see how the whole GNU/Linux stack works, but not something you'd use practically.
I've tried it before, the speeds are abysmal to the point of being unusable. It took me 3 days to download something that was only 50mb when I last tried it.
Magic Wormhole protocol. There's a lot of clients out there. Here's some: