Re: device ID
Can you explain in some more detail what you want? An (hypothetical) example would be fine.
When talking http and browsers, the usual way is to put a cookie on the device. Different devices have different cookies. But so do different (Windows) accounts on the same device. And if I enter private mode, I've got a different cookie each time. That's the best don't track trick that exists.
When talking pop3 and ftp I don't think it's possible.