Bluejacking is sending anonymous, unwanted messages to other users
with Bluetooth-enabled mobile phones or laptops.

Bluejacking depends on the ability of Bluetooth phones to detect and contact other Bluetooth devices nearby. The Bluejacker uses a feature originally intended for exchanging contact details or “electronic business cards”. He or she adds a new entry in the phone’s address book, types in a message, and chooses to send it via Bluetooth. The phone searches for other Bluetooth phones and, if it finds one, sends the message.

Despite its name, Bluejacking is essentially harmless. The Bluejacker does not steal personal information or take control of your phone.

Bluejacking can be a problem if it is used to send obscene or threatening messages or images, or to send advertising. If you want to avoid such messages, you can turn off Bluetooth, or set it to “undiscoverable”.

Bluetooth-enabled devices may also be at risk from the more serious Bluesnarfing. Bluesnarfing is the theft of data from a Bluetooth phone. Like Bluejacking, Bluesnarfing depends on the ability of Bluetooth-enabled devices to detect and contact others nearby.

In theory, a Bluetooth user running the right software on their laptop can discover a nearby phone, connect to it without your confirmation, and download your phonebook, pictures of contacts and calendar. Your mobile phone’s serial number can also be downloaded and used to clone the phone.

You should turn off Bluetooth or set it to “undiscoverable”. The undiscoverable setting allows you to continue using Bluetooth products like headsets, but means that your phone is not visible to others.