What is the use of the SAM missile battery?

[Dr. Dr. Doktor]

Is there any reason for building the SAM missile battery? The reason I ask is that it says in the civilopedia thet it will partially protect your city from enemy bombing runs. When it says 'city' does that mean only the actual city, or does it include the surrounding landscape? The point I am trying to make is that I have never seen the AI bomb my cities directly with bombers. They bomb the surrounding landscape but never the city itself.
I think the civilopedia is very unclear on this issue. I tried to search for an answer in various threads but the result was nil.

I am also asking because I am trying to make a modification wich makes use of the (new?) option of government specific wonders. In the case of a fascist gov. i wanted to make Speer's Cathedral of Light which gives a SAM site in every city. But is that a waste of time?

 

[friedmad]

It would seem that SAM batteries give your city 100% protection against enemy bombing runs. In all my games that i've built these bad boys, the enemy doesnt even attempt a bombing run - i guess theyre so afraid of getting their planes shot down that they dont even attempt the mission

Also, you will need 4 of these puppies built in order for you to build the SDI small wonder after you research Integrated Defense. Highly recommended since SDI protects EVERCY city in your empire from nuclear attack - 75% success rate at lasering the missile out of the sky - pretty cool animation too if I do say so