Your view of the internet only applies to things that aren't the internet. There exists no real governance or real ownership on the internet. These things do exist in some capacity, for the most part, in the physical world within national boundaries. Even still, if this were the physical world and some house existed, with an open door and outside the generally agreed upon distinction of what private property is, then you'd bet your ass I'd walk in and snoop around. If the owner came by and said "Hey! This is private propertay. I'll have you arrested!" then he'd certainly have the right to do so. I could then argue that there was no reason to think that this was private property because the door was open and it looked like public facility.