Sites only accessible to people on a network which is linked to the internet are not part of the public internet (for instance, my router's configuration page i

Sites only accessible to people on a network which is linked to the internet are not part of the public internet (for instance, my router's configuration page is most definitely not part of the public internet). A proprietary browser-based application running inside of a corporate network would not be part of the public internet, unless it is specifically designed to be accessible to anyone with a browser. The basic rule of thumb I would use is that something is on the public internet if anyone with a browser in a country with no filtering of the internet can reach it, given the proper passwords and so forth (and without using a VPN or similar tunneling to make it appear that they're elsewhere).