After walking through Circuit City and finding nothing worthwhile, I headed back outside of the Santa Monica storefront onto 4th St. There, I decided to take a few photos of the nicely arrayed "STORE CLOSING Sale!" signs. As I took the first picture from the public sidewalk, an employee told me I couldn't take photos. I calmly informed him that I could since I was on a public sidewalk and continued shooting. He asked me some more questions and I ignored him and continued to photograph the signs.
Then he got on the phone to call someone-- I thought he was trying to intimidate me, but maybe not. After getting bored taking photos of the signs in the store, I began walking back to 3rd St. Promenade. The employee was still on the phone. As I told him to have a nice day (really, I wan't even being snide, it was my way of letting him know I was leaving), he said to me, "they'll be coming to get you soon!" And with that I spontaneously laughed out loud and got a little ticked for the first time.
I wasn't really worried about the Santa Monica PD coming to arrest me, no matter what story he told them-- the cops here are professional and understand the laws about photography as well as I do. What ticked me off was he was still trying to intimidate me. At that point I took a couple photos of him for the first time, until he hid behind a utility box.
The cops haven't chased me down yet.