Public Reserved Land or Private Reserved Land?

In KL/PJ city, every inch of land is so precious that lot of people are trying to take advantage to gain extra inches of public land for private use.

This is original backyard view as built by the developer, a 10 feet buffer zone between the backyard with the road shoulder.


This is what had been extended by the house owner. The plants are cleared, and are replaced with a piece of concrete wall:


Is this legal? Can these house owners claim ownership of the 10 feet buffer zone land?