In many parts of the world, especially in
crime-prone societies, it is a common practice for home owners to spend huge
amount of money to build concrete fences around their residences. The walls are
so high that the houses behind them are hardly visible, except in cases where
the houses are multi-storey; and they are so hard that even bullets cannot
pierce through them. To add to that, sophisticated electronic security
appliances are installed to enhance seamless security for the comfort of those
who live in those homes.