"I have Control Over Your Cell Phone"

Read this and be afraid.

Imagine someone watching your every move, hearing everything you say and knowing where you are at every moment. If you have a cell phone, it could happen to you. 13 Investigates explains how your cell phone can be secretly hijacked and used against you - and how to protect yourself.

After four months of harassing phone calls, Courtney Kuykendall was afraid to answer her cell phone.

The Tacoma, Washington, teenager was receiving graphic, violent threats at all hours.

And when she and her family changed their cell phone numbers and got new phones, the calls continued.

Using deep scratchy voices, anonymous stalkers literally took control of the Kuykendall's cell phones, repeatedly threatened Courtney with murder and rape, and began following the family's every move.

This is a frightening situation but for us it raises the greater and ominous problem of how the techniques used to terrify this woman might be used to monitor your cell phone activity and steal your valuable personal information. Here is why we are concerned.

Spyware marketers claim you can tap into someone's calls, read their text messages and track their movements "anywhere, anytime." They say you can "catch a cheating spouse", protect your children from an evil babysitter and "hear what your boss is saying about you." And while you're spying on others, the Spyware companies say "no one will ever know" because it's supposed to be "completely invisible" with "absolutely no trace."

Security experts say it's no internet hoax.

So, be careful and report any suspicious behavior to the authorities.