Bluejacking is the sending of unsolicited messages over Bluetooth to Bluetooth-enabled devices such as mobile phones, PDAs or laptop computers, sending a vCard which typically contains a message in the name field (i.e. for bluedating or bluechat) to another bluetooth enabled device via the OBEX protocol.
Bluetooth has a very limited range, usually around 10 metres on mobile phones, but laptops can reach up to 100 metres with powerful transmitters.
The name originated with a user named ajack on esato.com. Ajack was in a bank, searching for other BT enabled devices. When he found a Nokia 7650, he sent the owner a message saying "Buy Ericsson". He called it bluejacking, and it stuck ever since. Ajack together with Droll subsequently developed a utility for Symbian UIQ called SMan which was the first bluejacking software for a smartphone. Applications designed for Bluejacking such as MobiLuck ,Easy Jack or recently Nokia Sensor are launching the MoSoSo (Mobile Social Software) Market.
Some people think that the term bluejacking comes from Bluetooth and hijacking. While that certainly sounds logical, a bluejacker doesn't hijack anything: he or she merely uses a feature on the sender and the recipient's device. Both parties remain in absolute control over their devices, and a bluejacker will not be able to take over your phone or steal your personal information. It should be noted that "jack" on many college campuses means "to pull a prank"- to jack a dorm would be to pull a trick or prank them - this too may be an origin of bluejacking.
Bluejacking is usually technically harmless, but because bluejacked people don't know what is happening, they think their phone is malfunctioning. Usually, a bluejacker will only send a text message, but with modern phones it's possible to send images or sounds as well. Bluejacking has been used in guerrilla marketing campaigns to promote advergames.
With the increase in the availability of bluetooth enabled devices, these devices have become vulnerable to virus attacks and even complete take over of devices through a trojan horse program.
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