These comparisons are getting pretty tenuous, don't you think?
If you run foo.com, and you open it to the public, then you have made the decision to allow the public to use it. You've got a DNS record that tells the world they're welcome to access your site. On the other hand, if I sit outside your house and use your open WiFi to scan for computers inside your house with open ports, I'm probably committing a crime. If you have not made your desktop machine public, my accessing it is almost certainly against your wishes.
By your logic, just because I didn't password protect it, doesn't mean it's legal open for you to load in a browser.