Unless that computer's in his head, I'm telling you they don't check every passport - every time.
Like I said, we fly into Buffalo...and our CA friends drive across to pick us up. We drive across the Canadian/US border at least 4X/yr. (twice - each way).
Could he be punching in our passport numbers as he's talking with us? I suppose. But, I'm also pretty sure they have bar codes on them (would seem a lot simpler to scan them).