Well...let me chime in for a minute...
I can care less if a honest, law abiding citizen wants to carry anything for personal self defense. Unless it's used, I may possibly never know what joe-schmoe is carryiing.
Crooks have a funny way of making themselves known...Usually by breaking the law...D'oh!
I've taken only two collapsable batons from people, both were involved in other "activities" and both were charged accordingly...
I "found" 4 guns last year:3 on people, one in a car. 3 out of the 4 went to Federal court, one was remanded back to the State penal system,a s he was a Parolee-at-large..
Last year, lots of knives, mostly from homeless types who brandished. I had two cases in which pepper spray was used: One case was clearly self defense, but the Supervisor on the scene gave me grief for not arresting the victim who sprayed (it's not a crime to defend yourself, and my report reflected that). The other incident was clearly an assault, and the peron was charged accordingly.
Justa few weeks ago, I was picking up a shoplifter from one of the chain stores, and noticed a clip sticking out of a customer's pocket. I recognized the knife as a Benchmade AFO, and auto, which is illegal in California. If I wasn't dealing with the speed-freak guy who boosted a pack of AA batteries, I would have spoken with the knife-carrying citizen, of course, but then again, I have more important things to do...Discretion is a wonderful tool...
The moral of the story: Of all the incidents I pointed-out, only one was with an honest citizen, and he wasn't arrested. That's not to say that in a self defense situation the victim may be on the end of legal action, it's just unlikely, unless a firearm or shooting, etc, something with deadly force or serious injury will ALWAYS bring an in-depth and thorough investigation.
--dan