Who do you call when your personal cell phone has been turned into a spying device, tracking your family's every move, and giving an anonymous stalker a view into your private life?
Three Washington state families say it happened to them and left them feeling like they were living in a horror movie.
"They say you're going to die, we hate you, we're going to murder you," said Heather Kuykendall, one of the alleged victims. And the families say no one seems to have an answer as to how or why it happened.
The police say they are stumped, but they have not ruled out the possibility that the alleged victims are making the whole thing up.
The families say the calls come in at all hours of the night, threatening to kill their children, their pets and grandparents. Voice mails arrive, playing recordings of their private conversations, including one with a local police detective.
The caller knows, the families said, what they're wearing and what they're doing. And after months of investigating, police seem powerless to stop them.
Cell phone companies are skeptical. "We are unaware of any technology that would allow the activity that's being reported here," said Sprint spokesman Matt Sullivan. "We are partnering with law enforcement to investigate. We're not exactly sure what is being done to these phones."
But, in an age of rapidly advancing technology, some surveillance experts told ABC News it's all too easy for hackers to turn your cell phone against you.
James Atkinson, an electronic surveillance expert, told ABC News cell phones can be operated remotely. "You can take photographs remotely, you can track the person's position, you can figure out where the phone is," said Atkinson. "Most cops have no idea how this is done."
The Kuykendall family's troubles started in February when 16-year-old Courtney Kuykendall's cell phone started sending text messages to her friends -- by itself, the family said.
Then the threats came. A scratchy voice called daily, sometimes to say that the entire family's throats would be slit, Courtney's mother, Heather, told ABC News.
But when the Fircrest, Wash., police tried to find the culprit, the calls were traced back to the Kuykendalls' own phones -- even when they were turned off.
It got worse. The Kuykendalls and two other Fircrest families told ABC News that they believe the callers are using their cell phones to spy on them. They say the hackers know their every move: where they are, what they're doing and what they're wearing. The callers have recorded private conversations, the families and police said, including a meeting with a local detective.
Many of the voice mails sound like a teenager's prank. "Sometimes they say real juvenile things. Sometimes it's really scary," Kuykendall said.
In one of the messages, which Kuykendall played for ABC News, the caller said, "I know where you are. I know where you live. I'm going to kill you."
Kuykendall, her sister, Darci Price, and her neighbor, Andrea McKay, who also claim to be victims of similar harassment, have named the callers "Restricted," the name that pops up when the calls come in.
Kuykendall, Price and McKay say their families' phones have turned on by themselves when they were switched off. The ring tones have changed on their own.