In my view, TASER ECDs, particularly the C2, are a wonderful "less lethal" option for security officers.  Unlike police officers, security guards, as a general rule, are not required to subdue subjects or make arrests.  Still, security guards are sometimes placed in harm's way, by the very nature of their duties.
By putting more licenses in your pocket, you increase the chances that you will put more money in your pocket as well. Don't be caught unprepared when opportunity knocks.
Before I explain how to get a guard card, I should take a moment to explain what a guard card is and why you need one in order to work as a security guard in California. In California, security guards are licensed by a state government agency called the Bureau of Security and Investigative Services (BSIS for short).
My father, a long time Deputy Sheriff and lifelong shooter, had a somewhat different opinion.  He was a large and jovial, but soft spoken man who tended to look at firearms from a more pragmatic point of view.  He felt strongly that people cannot defend themselves adequately with firearms that they never shoot.