Yesterday on the bus, I received a message on my mobile phone: “Pepperoncino sends you a Bluetooth message”. One is too curious… it was a pornographic image. Realizing I had just been bluejacked, I hopped off the bus and waited for the next one. I admit my reaction may be exagerated, but on the same day, I started to surf the net to find out if people had created smarter uses of the Bluetooth technology (see how it works).

This field is certainly an interesting one since unlike any other mobile communication mechanism Bluetooth is totally free.

Bluejacking is the act of passing anonymously a note via Bluetooth to a random recipient. To bluejack you have to save a message in the ‘name’ field of your PDa or mobile, for example, “I love your haircut”, then send it via Bluetooth. A list of enabled devices within 10 meters appears on your phone; select one of them and off you go. Recipients must, however, have Bluetooth switched on and accept the incoming data.
The fun generally lies in watching the reaction of the recipient, given his proximity.

The possibilities it offers look illimited: from sexual practices (prostitutes looking for clients, toothing or harrassment), illegal location-based spamming as you pass near a restaurant or shop, to sheer annoyance, although it’s possible to block anonymous messaging. There is also the problem of accidentally sending your phone number with your Bluejack message, exposing yourself to unwanted calls.

Then there is the issue of Bluetooth security vulnerabilities: to warn users over the peril of being unaware that Bluetooth is enabled on their hardware and that the security features are inactivated, a British researcher created Red Fang, a program that can “sniff” neighbouring Bluetooth-enabled devices unprotected by default security settings and steal them information.

But users came up with a series of Bluejacking “good” practices. To name just a few:
– Bluetooth Against Bush uses bluetooth enabled devices to create moments of solidarity for opponents to George W. Bush and his policies.

– Community activities: dating or gaming could take a new dimension through the anonymous component of bluejacking. Users could, for example, invite others to play mobile games on crowded commuter trains.

– I found on mbites, the idea to introduce Bluechalking: inspired by Warchalking – the practice of “marking a series of symbols on sidewalks and walls to indicate nearby wireless access”. Bluechalking would indicate that someone with a Bluetooth-enabled phone is often in the area, using the Bluetooth symbol and the name of the device. The concept has been declined in tagging a t-shirt or a bag. “The idea would be to explore an entirely new kind of wireless social interaction. A kind of consensual Bluejacking.”

– Among the minus sides of Bluejacking, I had listed spamming, but some users might welcome it if they could actually chose to be sent electronic coupons, promotional messages, cinema schedule and other information.

– TagText.com is a youth oriented site that lets you download (for free!) pictures of avatars to use as wallpapers, messages, or for Bluejacking. Their idea is that “Local Free Messaging (LFM) – by Bluetooth and Infrared is an area to monitor as it could just be one of those consumer-led market-changing paradigms”.

A more dilagated use of the technology is called Piconet: when Bluetooth-enabled device come within a range of each other they can establish a connection. Each Piconet has one master (generally, the unit that set up the connection) and up to seven slaves.

See Mbites, Pocketpcthoughts, Bluejackg, Rainier PR,