The best thing I've read on this subject was written by Hiibel himself for the Christian Science Monitor:
He fought the law, and the law won.
He says:
"Here's why this was so important to me: I don't believe that the authorities in the United States of America are supposed to walk up to you and ask for your papers. I thought that wasn't lawful. Apparently I was wrong, but I thought that that was part of what we were guaranteed under the Constitution. We're supposed to be free men, able to walk freely in our own country - not hampered, not stopped at checkpoints. That's part of what makes this country different from other places. That's what I was taught."
"And it's not just because it's in the Constitution. It's something that you just kind of know. It's kind of obvious. If you haven't committed a crime, you shouldn't be harassed by the police. If they suspect you of something, I don't see why they shouldn't explain it. I wasn't violent. And it was proved later in court that I hadn't committed any crimes."