Different people

There is almost no closure between one of the neighbors, the the others have lately erected a very high one, as you may see from this picture.

No ball from the children can now go to them by error, nor can anyone see in their courtyard, behind their house. In front of the house there is open ground, nothing hints of the separation.

Looking at the tall wall, I wonder what made them erect it, as not others around here use to do that.

I understand the need to feel private in its own place, but less not to see sometimes the others children enjoying themselves - which one made them erect such a high separation?