It used to be my habit early in the morning to get coffee, a muffin and a newspaper and sit in my car reading. I would usually find a deserted parking lot and hang there for awhile.
After doing that for about ten days in a row, one morning a squad car pulled up behind me, and told me that they received a call from a tenant in an apartment overlooking the parking lot. I hadn't realized there were apartments over the store fronts, and so it never occurred to me that anyone might be living there.
Anyway, the cops said that a lady tenant had called them to check me out. She was afraid I was stalking her. They were very polite, and asked me all kinds of questions about what I was doing there. Then they asked for my driver's license, which they took back to the squad car for a background check.
Then they came back, and politely suggested that maybe I should find somewhere else to drink my coffee.
This is America (well, Massachusetts, anyway), I'm a US citizen, and I was not bothering a soul.
But I was still asked to show ID because someone found my behavior suspicious, and I was fine with showing my ID because I understood the concern.
I think the cop should have asked this guy for ID as a matter of course. I'm not saying the guy should have been arrested for refusing, but he definitely should have been encouraged to leave the neighborhood after being checked out.
They did that because you were sitting in a car, there was reasonable expectation that you drove the car there, and they have the right by law to examine your license to operate that vehicle. Had you not been in a car, while they could certainly ask for you to produce ID, they had no way to demand it if you refused to comply.
Beauseant!