Imagine you're driving to work on a cold February morning and you glide past a forest of billboards. The weather looks like it's turning, so you flip from an alt-rock station to a news station to check it out. Suddenly the billboards are changing, too, from trying to sell you a GameCube to pitching minivans.

By changing your radio station you've sent a message to the marketers watching your every move. Their interpretation? You're a middle-aged commuter who listens to talk radio stations, ready to be sold a responsible automobile.

This is the state of personalized marketing on the interstate just outside Sacramento, California. MOBILTRAK's radio monitoring system (RMS) allows marketing companies to find out which radio stations passing motorists are listening to. Based on this data and some demographic assumptions, the Smart Signs change what they display. MOBILTRAK boasts that all electronic devices – portable stereos, clocks, cellphones, computers – that emit weak electronic radio signals and frequencies can be detected.

So we don't just have to worry about overzealous anti-terrorist governments eroding our privacy. Now a new threat is coming from marketing companies fighting for your dollar.

The easiest way to keep tabs on customers is via the Web. Web servers use the cookies stored on your hard drive to tell them where you've been, what you've been looking at and what you buy online. Banners and pop-up windows then sell you products that are appropriate to your interests.

But computers aren't the only devices online any more. In the near future, TiVO (digital TV) subscribers might get personalized ads adapted to the kinds of things they want to buy.

As laws against spam are starting to become a reality, marketers have pushed into the world of mass text-messaging through cellphones, PDAs and other online mobile technologies. In the UK, users have been getting messages from "secret admirers." Random phone numbers show up on their screens, and return calls reveal the message has come from a marketing company.

It turns out that efforts to control text-messaging spam might slip through the tangled net of bureaucracy. Janet Feasby, director of public affairs and communications with Advertising Standards Canada (ASC), clarifies her organization's mandate: "We deal with the content of advertising, not the medium used to deliver it."

She refers me to the Canadian Radio-Television and Telecommunications Committee (CRTC), where a rep explains that it "doesn't deal with regulating alpha-numeric messages, even if they are sent over phone lines."

Next I try the Canadian Marketing Association, where director of communications Ed Cartwright assures me that the CRTC does have jurisdiction over everything sent over telephone lines.

At this rate, by the time we've created some rudimentary rules to deal with unsolicited text-messages and eavesdropping on radio signals, the marketers will have moved on to the next technological innovation, harnessing its anarchic powers to sell their wares.

"New technology is really changing the way marketers are interacting with their customers," Cartwright says. "Spam and mass text-messaging have the potential to jeopardize the Internet's use for reputable marketing."

Referring to MOBILTRAK's scanner, he says he feels confident that privacy advocates in Canada will ensure the device cannot being used to identify individuals, only their broadest consumer patterns.

Even if the CMA does an exemplary job of subduing intrusive marketers, advertisers always seem to stay one step ahead. The appropriately named Alien Technology has invented the radio frequency ID tag (RFID), an off-line device that periodically sends radio signals back to marketing headquarters on usage patterns, and could result in a reminder e-mail when you're running low on shampoo.

The progressive nature of new technology, and the ease with which advertisers harness it, allows stealth marketing to target consumers before they know they've been marketed to.

Woody Norris of American Technology has invented a processor that projects sound in a focused beam, much like laser-focused light. It's liberating to imagine listening to music beamed right at your head without your roommate hearing, but imagine receiving a marketing message directed in the same way without being able to tell where it's coming from.

Companies such as McDonald's and Wal-Mart have been experimenting with ways to direct this sound laser at target customers. Essentially, it would follow consumers around and plant auditory messages in their heads.

The dystopian world of Minority Report, in which billboards address the characters by name, might not be far off.  

next@nowtoronto.com