Similarly, the computer model might lead us to think that we're programmed. But such a belief would have us "dumb down" our educational system, substituting programming for teaching, and being programmed for learning.
Finally -- although there are many other possible examples--computers may model rationality (they don't, actually), but they sure don't touch emotion. The computing metaphor treats emotion as a mere epiphenomenon, an accidental byproduct like the heat generated by a TV set. As "information" appliances, computers are already biased against emotion, preferring a "just the facts, ma'am" world. But emotions are about what things mean to us and thus enable information to matter. They are the engines of personhood, not a byproduct.
Now for the hard part. Suppose for the moment that the Web is as defining of the coming age as the steam engine and computers were of theirs. How are we going to understand ourselves in light of the Web? We can already begin to hear ourselves thinking of a memory lapse as a "broken link."