This testimonial comes from Ellie G., a 13-year old girl from Surrey, UK. In October 2003 she started a web site that is now a busy meeting place for techie pranksters swapping stories and offering advice about their covert missions. It’s a place where cell phones and text messages are the weapons, malls and train stations are the hunting grounds, and the victims survive with little more than a tinge of embarrassment or confusion.

Bluejacking — described by some as a modern version of ringing someone’s doorbell and running away — allows owners of some cell phones and personal digital assistants to send anonymous text messages to nearby strangers owning compatible devices. Since Ellie launched www.bluejackq.com, articles about her, the web site and bluejacking are popping up not only on technology web sites such as The Register and Slashdot, but also in mainstream media outlets including the BBC and CNN. Bluejacking is possible because of a technology called Bluetooth, found on an increasing number of cell phones, PDAs, computers and even automobiles.

If you’re wondering why this is taking place now and involving a technology you’ve never even heard of, you’re not alone. A 2002 survey of British, Japanese and American citizens showed Bluetooth familiarity highest in the UK and lowest in the U.S.
In Europe, the mobile phone industry drives innovation. In America it’s the PC industry, and in Asia, it’s consumer electronics, says Mike McCamon, marketing director at the Bluetooth Special Interest Group (SIG), an organization focused on promoting the technology. With the help of Apple’s AirPort, Intel’s intense marketing of Centrino and WiFi “hotspots” everywhere from Starbucks to airports and hotels, millions of Americans now know about and use it every day. While technologically different from WiFi, Bluetooth’s supporters hope the technology will bring the benefits of wireless connectivity to mobile phones users everywhere.

Created in 1994 by the Swedish telecommunications giant Ericsson, Bluetooth, named for the Danish king who in 950 AD united Denmark and Norway, was a technology that the company hoped would unite the mobile world. Establishing a basic technical concept for the transmission of data across short distances (under 30 feet) via low range, low power radio waves, Ericsson then gave the technology away for free. The company hoped other manufacturers would include it in their products and thereby provide a common standard that could be used to eliminate the need for cables on things like earpieces and cradles for data transfer to and from personal computers.

In 1998, Ericsson joined with five other companies – Nokia, IBM, Toshiba and Intel – to form the Bluetooth special interest group (SIG). In January, the group welcomed its 3,000th member. By the end of last year, industry estimates put the number of Bluetooth-capable products shipping per week at 1 million, and the dream of Bluetooth proponents — a world of mobile electronics and peripherals working together without wires — is beginning to take shape.

With greater Bluetooth awareness and better access to more advanced cell phones from brands including Nokia, SonyEricsson and Siemens, tech-savvy Europeans are the ones bluejacking their neighbors in malls, train stations and even McDonald’s. U.S. wireless carriers lag behind their trans-Atlantic counterparts in the deployment of Bluetooth-capable devices (between 12 and 18 months), but they are taking note of and moving to accommodate growing consumer interest. With wireless phones reaching an estimated 160 million people across the U.S. alone and some 50 million more subscribers projected in the next five years, there is an ample supply of potential users.

“I’d be very surprised if, at the end of this year, there wasn’t a Bluetooth phone available from pretty much every carrier,” said Steve Deutscher, director of product management for Motorola’s companion products. At present, four of the six U.S. cell phone companies offer such devices.

Once a person gets a capable phone or PDA, successfully bluejacking someone is relatively simple. The prospective bluejacker must simply create a new entry in their phone’s contact list with the message they want to send as the name of the contact. Instead of making a contact with the name “Roger”, for example, the name might be “Is that hairpiece real?”

In order to initiate a connection with anything (such as a wireless headset), Bluetooth-capable phones can send out signals to “sniff” for other, compatible devices in the immediate area. Nearby phones reply with whatever identity information the owner has chosen to put into his or her device. Some may simply list T610, while others might have a name, like SMan, Sparky or Plucky. Depending on the number of Bluetooth-capable phones in the area, a bluejacker might see several names displayed on his or her phone’s screen. The initial reason for making these phone-to-phone connections possible was to facilitate the exchange of contact information such as that found in an address book. Bluejackers, however, have come up with a way to use the feature for entertainment purposes. Once a potential victim has been located, the bluejacker simply sends them the contact from their phone book, leaving the victim wondering if their hair really does look fake.

In the same way that someone can get an e-mail and read the subject line before opening or deleting it, a bluejacker is able to get his or her quip across without requiring a victim to accept anything or establish a secure phone-to-phone link. Messages can be so long because the “name” field in a contact list can include nearly 250 characters. Because Bluetooth does not require a phone to connect to the Internet or connect to the service provider’s network (as do other types of messaging), there is no fee associated with the practice, either.

To a bluejacker, thrills come from the fact that in ideal cases, the recipient of one of their messages won’t have a clue as to who sent it. Because of Bluetooth’s short range, bluejackers also need to be in close proximity to their “victims”. Dozens of energetic stories about successful escapades fill the message boards on bluejackq.com as enthusiasts describe the places where they found and messaged unsuspecting victims or even followed them around a mall, all the while sending multiple messages and reveling in the victim’s sheer befuddlement.

“I just like the looks on the bluejacked people’s faces when they see an ‘unknown’ message popping up on their screen,” wrote Tim De Wachter, a 15-year-old living in Belgium who replied to questions about bluejacking over e-mail. De Wachter remembers reading about the practice in a computer magazine where the editors tried bluejacking. He then visited bluejackq.com and a few days later bought a Bluetooth-capable phone.

“It’s like being a kid again and up to no good – like the old knock on the door and run away kinda thing,” wrote Paul Brown, a 28-year-old from the UK and another frequent contributor to the site’s message boards. “I also like to see when I have cheered someone up,” he said via e-mail.

But despite the innocuous and playful intentions of many bluejackers, the mere concept of receiving an anonymous, cryptic or potentially offensive message from someone guaranteed to be within a 30-foot radius can potentially do more than cause confusion. While many mobile technology enthusiasts know about Bluetooth, many people owning and operating compatible devices on a regular basis have no idea that they could even be bluejacked.

But the potential for real damage, at least by bluejackers, seems slim. Pranksters do not make a secure connection to their mark when sending a message, and what many people don’t realize is that a phone’s Bluetooth capability can simply be turned off. The device can also be set to an “undiscoverable” mode, preventing it from being accessed by anyone nearby. A potentially more dangerous practice that has recently popped up on the radar screens of those following these types of activities is bluesnarfing. Bluesnarfers try to establish connections with a nearby Bluetooth-capable devices and retrieve address book, calendar or other information. Turning a phone’s Bluetooth functionality off or to undiscoverable mode greatly reduces the risk of this happening, however. Industry, at least at this point, believes user education is key to reducing the spread of these behaviors, because if anything has the power to kill a nascent technology like Bluetooth, it’s spam. Imagine receiving enough unwanted messages on your phone such that the memory completely fills up, leaving no more room for important data. Let’s not even think about the possibility of viruses. Users need to be aware of the ethics and drawbacks associated with sending messages, while simultaneously being prepared to deal with the potential drawbacks.

“It’s obviously the user’s responsibility to be using the [phone] properly,” said Laurie Armstrong, manager of media relations and corporate communications at Nokia, Inc. “We’re trying to educate our users...along with that comes education about potential risks.”

Despite those potential risks, Bluejacking’s proponents remain resolute. The “bluejacking ethics” section of the bluejackq.com web site promotes bluejacking as a way to have fun and communicate with other mobile phone and PDA users. It will only take a few misuses of this technology to spoil it for everyone else, the ethics section says, asking users to “try to preserve it for as long as we can.”