To be honest, any person that doesn't know what Airsoft is would probably think the same as the person that called 911.
I'll admit I don't leave the city every time I want to Airsoft mainly because the drive is insane and at one point we weren't even old enough to drive; what I think is more important is not necessarily where you play but how you react to people who have seen you with an automatic rifle in full BDU. When we played and a hiker came by we would simply stop the game drop our guns and one of us would quickly explain to the hiker/biker what the deal was. We didn't have much problems with that methodology however, not everything is so cut and dry.
And because of this we usually would play up to about half a mile North of the residential areas along the base of South Mountain and we never had any problems after that. People just need to be smart about where they play but mainly how they act and react. If you are silhouetting your self on the top of a hill or playing your games on bike/hike paths there will eventually be a problem.
Murphy's Law!!!
I never had a slice of bread,
Particularly large and wide,
That did not fall upon the floor,
And always on the buttered side.
~SWED [smilie=armata_pdt_06.gif]