I came across this thread on digital Photography School where people post their experiences with people’s reactions to seeing a photographer. Some excerpts:

I find taking night shots in and around downtown dangerous. I attract too much attention, let me rephrase that…my tripod attracts too much attention. Drivers will start trying to see where my focal point is and start veering off the road, sometimes right at me!

A couple of months ago I actually had some old lady call the police on me. In her mind, somebody setting up a tripod by a lake was most likely robbing her neighbor

Speaking of public photography, I took this one of my lunch at Daikokuya in Little Tokyo, LA. People were looking at us, but no one told us to stop taking photos inside their establishment.

Unegi