After analyzing the appeal (or lack of it) of various ads – it was the heyday of the old Volkswagen Beetle, the ads for which were extremely attractive – students paired off into teams. Each team developed a product and a commercial to sell it. Some were unforgettable; I remember them over forty years later.

During that unit on advertising, I one day brought to class a one-ounce medicine bottle and set it on my desk. “The school nurse,” I told the class, “is concerned about the air circulation in the classrooms. So I’m going to open this bottle of perfume, and as soon as you can smell it, raise your hand.”

One by one the hands went up, spreading toward the back of the room, till everybody was indicating he smelled it. “Thank you,” I said. “Now, two things. First, this is tap water, not perfume. Second, never believe you can’t be manipulated by the power of suggestion.”

It was the perfect moment to introduce Grimm’s fairy tales, with their old German combination of primal childhood fears and cautionary morals. Why is the Big Bad Wolf so bad? Not only because he’ll eat you as soon as he can, but because he cons you first into thinking he’s a really sweet guy. He fools Red Riding Hood and two of the Three Little Pigs; she’s saved by the timely (and unrealistic) intervention of a woodcutter, and the Practical Pig by his wisdom and foresight. Only one of the four sees through him.

That led naturally, shortly afterward, to Oliver Twist and Bill Sykes, the incredibly ill-favored, yet persuasive psychopath who runs a team of youthful thieves and, for a while, at least, manipulates Oliver, as well. Then we moved on to A Merchant of Venice. The thought for the day, written on the chalkboard as we read through Act I, was, “If anything seems too good to be true, you can be sure it is.” Bassanio wants badly to borrow some money from Antonio, a wealthy merchant who, at the moment, is out of ready cash. So Antonio in turn borrows it from Shylock (whose name has ever since been a common noun). Shylock jokingly suggests the penalty for default be a pound of Antonio’s flesh. Antonio, cautious, suspects it’s too good to be true: “An evil soul producing holy witness is like a villain with a smiling cheek, a goodly apple rotten at the heart. Oh, what a goodly outside falsehood hath!” I don’t know if any of those long-ago students internalized all that, but if not, it wasn’t for lack of my trying.

Those were the days before the Internet. The blandishments and appeals of advertisers came to us then via what now seem like pretty primitive technologies. I have friends who remain in that situation, increasingly out of communication since so many of us no longer take the trouble to telephone or mail a note. An elderly clergyman I know resists the cyberage because, I’m sure, he believes the Devil is in his computer. He’s right, of course; but then, the Devil is in practically everything. He’s just a lot easier to find with a keyboard hooked up to high-speed.

A lot of very well-intentioned and knowledgeable people are trying to make that point to today’s students. It may be they’re reaching some, even many. But tragically, not all. Vermont this past week activated its first-ever Amber Alert when a 12-year-old girl went missing after an apparent rendezvous with a person she had become involved with on the Internet.

This is written as the search for the child continues and the debate revives over adolescent access to the obvious benefits and equally obvious perils of instant communication with people all over the world who may or not speak the truth or wish us well. If I had a dollar for every scam that appears on my screen from Nigeria (“I will send you cashier’s check for more than the price of your fine vehicle. You send me the difference in cashier’s check for shipping...”), I could take a week off and fly to Molokai. The Big Bad Wolf and Bill Sykes are still at large, on the Internet.

Our poor kids! Research shows that the prefrontal cortex of the adolescent brain, which controls emotions, restrains impulses, and makes rational decisions, is not yet developed. Most parents of teenagers respond to that with, “Tell me about it!” Our kids spend much more time in recreational and personal use of the Internet than those of us presumably past the age of easy susceptibility. Protecting them from errors and danger is impossible by surveillance alone; we can’t monitor every minute of our children’s cyberactvity. Facebook and MySpace are growing apace, and everybody wants to have a thousand certifiable friends.

There’s no one solution. Education is crucial, as much with the Internet as with sexual activity. Monitoring helps. The cops who roam cyberspace pretending to be lonely teens are a deterrent. But given the adolescent inability to be consistently rational, a good, healthy dose of raw fear might be a good idea. Because the Big Bad Wolf, our childhood nemesis, will never die.