Outside of the cybersecurity analogy, as an American, that's . . . very disturbing.
Much like someone open carrying a gun is seen as potentially a few seconds away from committing a Very Bad Crime, so is someone walking around your house uninvited.
England has some weird (to me) property privacy laws. IIRC, you cannot be charged for simply walking through someone's property as a shortcut. There's nothing they can do about it, you just can't linger on the property. I mean, it seems fine, I just haven't seen anything like it before.
It's the system throwing a bone to the general populace in order to maintain an extremely unequal order. Aristocratic landowners mostly do what they want, and there has been no land reform for centuries, so a few concessions were thrown in to allow peasants to make a living somehow.
Well cutting across someone's yard != walking through their house. My friends and I growing up would sometimes cut through neighbors' backyards to go somewhere, and while we didn't have formal permission, no one cared because we knew each other.
Much like someone open carrying a gun is seen as potentially a few seconds away from committing a Very Bad Crime, so is someone walking around your house uninvited.