Reading you guys, I must say I never thought about it from your view. As someone wrote, it is true irony, that in LA you have problems with that ( or California in general ). What about other states? Does your legislative is pretty much same for this issue across whole USA, or every state has particular law? And as for UK, I read also that you had problems after those attacks in London. I will write from my experience of photography.
To be honest, in Croatia I have no problems with this, except when I'm taking photos of railway stations, on street I never had problems to this date ( that could change, but I hope not ).
Also, believe it or not, least problems I had in Iran - yes Iran. I took photos there with no problems, what was forbidden to take pictures police or military would just show me "no-no" with finger and that was all.