(FORTUNE Magazine) – There's hijacking, carjacking, and now a far less dangerous but equally unsolicited form of harassment: bluejacking. Bluetooth, a radio technology that allows users to exchange data over short distances, is normally used for things like making wireless headsets work with desk phones.

But lately mischievous techies have been using it to send text messages to unsuspecting bystanders. A bluejacker simply saves a message in the NAME field of his phone--for example, "your fly is unzipped"--then chooses where to send it via Bluetooth. A list of enabled hardware in the vicinity appears on his phone; he selects his victim and hits SEND.

Often messages, delivered within close quarters on a train, for example, announce, "You've been bluejacked!" Other favorites are comments about fashion or surroundings.

Bluejacking, which is popular in Europe, hasn't exactly stormed U.S. shores because only about 1% of cellphones here are Bluetooth-enabled, says Seamus McAteer, a consultant with the Zelos Group in San Francisco. Still, what a creepy new way to reach out and touch someone. --Adam Lashinsky