The houses in our neighborhood are pretty close together. Each one is on just 1/3 of an acre, and really, no one knows where each property line ends and the next one begins. For those of us with fences, we can be pretty sure that the fence marks out the property line accurately, but who knows if the owners at that time had a survey taken before installing the fence.
To compensate for this lack of knowledge, whenever anyone cuts their grass, they usually just cut the grass up to the driveways on each side of the yard. Sure, this causes us to cut some of our neighbors' grass and them to cut some of ours, but who's measuring, right?
Apparently our neighbors to the right (who are trying to sell their house) are measuring.
They left this 12" strip of grass when they cut the lawn last week. Isn't that just silly? You'd think we had done something to tick them off ... I don't think we have. Who knows.