The usual* way to handle this is to have a small LED next to the mic/camera that shows when it's on -- and have it wired up to the device in series, such that it's software-impossible for the device to be powered without the light being on.

*: it's what we did on the One Laptop Per Child laptop, and I'm sure others have too.

Thank you for inventing the netbook and showing the ODMs how to make low cost PC notebooks.

Any idea where to get a CLI-from-boot notebook for teaching kids programming and encouraging a hacker ethic?

Thanks for the kind words! I haven't used it personally, but a programmer in my Twitter feed recommended this one that they've been using with their kids recently. (I don't think there's a heavy emphasis on CLI.)

https://tksstgiftguide.tumblr.com/post/167274832422/our-kids...

At least you only need to verify a switch once, it won't be compromised by software changes.

Assuming the switch does really cut the mic signal and doesn't instead act on a i/o pin which calls a function to disable the mic input. The second solution would be hackable.