> Buy an off the shelf processor chip, buy memory chips, buy some interface chips to provide access to peripherals and storage, solder them to a board I suspec

> Buy an off the shelf processor chip, buy memory chips, buy some interface chips to provide access to peripherals and storage, solder them to a board I suspect those things will become regulated and require either constraints built in or license to be able to purchase them. Then likely aveneues for connection will be required to verify devices are trusted (so, cellular companies, ISPs) and they will do this by associating devices that try to communicate with government issued cryptographic signatures that are built into chips etc. And yeah you could bypass everything but it will still be illegal. So a bit like you could build your own car but you won't be legally allowed to drive it on the road and you will incur huge liability if you try.