Better sit close, because I have a spooky tale to tell.

I like to wait up past midnight, then walk the dark alleys with my dog Beau. It's a peaceful time, and a relatively safe time to slip his leash off and let him sniff at his own pace. We move from shadow to shadow, the only sound our own crunch underfoot.

But lately, it hasn't been working. We'll walk ten steps down an inky black alley, and - boom! A spotlight mounted on a garage will be shining on us. It's as if someone heard us milling around, doing God knows what by their trash barrels, flicked a switch, and may be about to step into view, brandishing a shotgun maybe.

Of course, it was just a motion detector. But nowadays, as we walk the alleys, we set off one motion detector after another. Beau, who in a previous life was a wolf, sinking his teeth deep into innocent flesh, but is currently a poodle, looks at me with an expression of dubious consternation. I look right back at him, ditto. We are like prison- hardened Alcatraz escapees, suddenly tap- dancing in the searchlight beam.

It takes all the fun out of our walks on the wild side.

You can buy a spotlight with a motion detector for $16 at Home Depot. It's basically a lightbulb and a sensor. So everyone's getting them. I could probably even install one myself, and keep the bad guys surrounding my house night and day off- guard. The good guys, too.

So the scary story is that a sensor revolution is just getting underway. Sensors are like deformed microchips - though they work digitally, the information the process is analog. It's like a little computer with a tongue instead of a keyboard -- or a nose, or an ear.

If sensors proliferate like microprocessors did in the 1980s, their number will increase ten thousandfold in the next ten years. And motion sensors are the least of it. You can mount a tapeless video camera on a chip now for about two bucks. You can detect sights, sounds, changes in heat, light, barometric pressure, radiation level, carbon dating, and pH value.

And everyone will be using these things, every street sign, car bumper, and tree will have cameras and microphones and alarms press-mounted in it. It will be one of those "got-you/I-got- you-right-back" technology spirals, like Caller ID or radar detectors, where you can buy an infinite number of one-upping add-ons to prevent their detecting you, you detecting them, them detecting your detecting, and so forth. Everyone will be everyone else's Big Brother.

Convert these analog impulses back to digital and you have the entire world under constant electronic surveillance. Police departments merely have to mount detectors wherever street crimes typically occur, and street crimes will stop occurring there.

Now combine sensors with the Internet and program computers to fuzzily identify things like screaming, guns going off, sudden heat, and a heartbeat out of rhythm. Dispatch the nearest agents to contain the problem, and you have a globally decentralized real-time know-all emergency action system that makes global satellite positioning look about as state-of-the-art as moveable type.

It will be possible, walking down the street, to view the career resume, medical history, and arrest record of each person approaching you.

Think how difficult it would to create a fake ID in such a world. Have a nice day, "Mister Jones."

Fortunately, there is no conceivable way information like this can be misused. Right?

And unlike security issues that vex many of us today, there is no way to opt out of them. You can set your browser to "no cookies" but you can't set your life to "no sensors."

It is a future without secrets, without escape. In a sense, without free will.

Even if you deploy stealth technology and paint yourself with invisible paint, nonradar sensors will see you swooping down from the skies. They will know you by your engine heat, or your noise, or the fact that you are traveling at 1,1000 miles per hour. They will shoot you down.

Even if you are a child of the night, one of the dead and yet not dead, you are not immune. Your reflection does not show up in mirrors, so you are reasonably confident no video camera on a chip can photograph you, either.

But other sensors will see you. The motion of your cloak silently sweeping through a bedchamber. The antiquity of your dust. The hair of the wolf.

Or maybe it will be that electronic wallet, which everyone will carry around with them, on a chip embedded under your skin. It will include everything known about you medically -- blood type, dental records, prescription list, policy number. And in your case, certificate of death.

Hey, you with the teeth -- you're busted.