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.