In America, the law states that you are not required to provide ID to police unless you are suspected of a crime or it's a traffic stop.

But that's just what the law states, and cops don't care about that. They'll harass you until you lash out in frustration so that they have an excuse to beat the shit out of you and throw you in a cell.

So yeah, theoretically, I don't need to carry my ID if I'm just walking to the store, but I kind of do anyways in case I run into a cop with a bad attitude.