Like all communications technologies, Bluetooth has its share of potential security risks. Admittedly, they are less severe than Wi-Fi security problems because Bluetooth signals travel such a short distance.

One of Bluetooth’s major security glitches involves bluejacking. Bluejacking is not so much a security problem as an invasion of your privacy. It involves someone sending you an unsolicited message that may or may not be polite. In order for your Bluetooth-enabled phone to be hijacked this way, however, it first must be discoverable by others.

In essence, a bluejacker creates a contact in his phone address book that contains the message (rather than name, address, and other information) he wants to send. He selects this contact and then tells the phone to send it via Bluetooth. The phone searches for Bluetooth phones within 30 feet. The owner then sends the message anonymously to one of the phones on his list.

How can you protect yourself from this annoyance? You can try one of these:

• Make your phone hidden from other Bluetooth-enabled devices.
• Ignore the messages, unless you’re expecting one.
• Turn off the Bluetooth feature.
• Turn off the phone when you’re in a busy area where bluejacking is more likely to occur.

Bluejacking has a positive side: It’s also a way to send free text messages to friends and business associates. If you want to use this feature, then ignore the list of ways to protect yourself against it.