Bluejacking is easy. In fact, you can download Bluejacking software from the Google Play store, or from any number of other sites.
Some software lets you find "hidden" open Bluetooth connections. And you can typically send messages, pictures or even sounds.
Although Bluejacking is primarily used in sophomoric pranks, it can also be used for social engineering, which is one of the things the characters in Person of Interest use it for.
For example, you could send fake error messages to make someone believe his phone is malfunctioning. You could then offer to fix it for him and then install spyware once you have access to the phone.
The technology is easy to use. But a skilled hacker is also skilled at tricking people, and that's the real reason Bluejacking is such a threat.
The bottom line is that the phone hacking activity depicted on TV is exaggerated. The characters in Person of Interest remotely crack, take over and track phones far more quickly and easily than is possible in real life.
However, everything they do in the show is possible in principle, under the right circumstances. And in fact, nearly all the hacker talk and technical jargon used in Person of Interest is shockingly realistic for network TV, which usually dumbs down such language.
More importantly, I believe the show provides a valuable service by introducing the public to the kinds of things that are possible with a phone -- making them aware of the fact that a modern smartphone is, above all, the Mother of All Surveillance Devices.
All mobile phone owners should know that they're carrying a microphone, a camera, a tracking device and an automatic logging tool that records their electronic interactions with other people, as well as other activities. And they should know that these devices can convey that information without their knowledge.
Are you being watched, tracked and hacked right now? Probably not. But it's impossible to know for sure. In fact, the only way to be 100% sure that you're not being spied on by your phone is to get rid of it. In the meantime, watch a few episodes of Person of Interest. It's a great show, and it could give you a healthy dose of paranoia about what your mobile phone is theoretically capable of.
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