Every day, some of Hollywood's biggest stars pay the price of fame, when obsessed fans become stalkers, fixated on a fantasy that to them is very real. And in Los Angeles, ground zero for celebrity stalking, the police department has a one-of-a-kind "threat management unit" to handle those cases.
Actress Jennifer Garner recently got a permanent restraining order against a man who blogs about human sacrifice. She says he has terrorized her since 2002.
Michael Douglas' stalker threatened to cut up the actor's wife, Catherine Zeta-Jones, and feed her to her dogs.
Uma Thurman describes her experience with a stalker -- who was convicted in court -- as a nightmare.
And in the case of Brad Pitt, a woman once broke into his home, fed his dogs and slept in his pajamas.
Many celebrities are not overtly threatened by their stalkers, but the ordeal can still be terrifying.
The Los Angeles Police Department's team of highly trained detectives -- known as the threat management unit -- first banded together because of one star's violent death in 1989.
Rebecca Schaffer was a rising star with a lead role on the hit TV show "My Sister Sam" when she was murdered by an obsessed fan named Robert Bardo. Back then, there were no stalking laws in California or anywhere else.
Schaeffer was gunned down at her front door, and for California police officials, her brutal death was a wake-up call.
"She had to be the victim of a homicide in order for us to get the message that something needs to be done in the way of legislation to address stalking crimes," said Detective Jeff Dunn. "There is a fine line between fan and fanatic."
Dunn began what would be a long and often shocking career, working with celebrities to investigate the most aggressive stalkers.
"They've got access to a telephone and a computer and they can make our victims' lives a living hell," said Dunn.
In 2003, Britney Spears was followed by an obsessed fan. Masahiko Shizawa embarked on a 37-city obsession tour in pursuit of the recording artist.
"What we had was a Japanese business man, came to America on a tourist visa for the sole purpose of following Britney Spears around on her concert tour," said Dunn. "As far as [Spears] is concerned, he was completely delusional."
Dunn believes Shizawa used the Internet to not only track Spears' concert schedule, but her life from Louisiana to Los Angeles.
"We weren't aware of this guy until he showed up at her Hollywood Hills home and confronted the security guards," said Dunn.
Shizawa had been following Spears from the front row of dozens of concerts. Dunn says he traveled to her home in the South, and to her mansion in Hollywood. He sent the pictures to prove it.
"You can see he was in very close proximity to her at several points in time," Dunn said, shuffling through the photos. "Here's one that if you were Britney Spears you would find very concerning. Here's a picture of her limousine as she is leaving one of the concert venues and on the back of the photograph he says 'I'm chasing you.'"
Detectives say the most dangerous part is that Shizawa believed he had a relationship with Spears.
"We knew there was going to be a long-term problem until she dealt with it," said Dunn.
Advised by the stalking unit of the potential danger, Spears got a restraining order. When Shizawa's tourist visa expired, that restraining order was used to get him on a no-fly list. He's since tried to reenter the United States five times and each time he has been stopped.
"Typically if you dig into these cases you find much more disability and disorder than how it appears on the surface," said Reid Meloy, who is widely regarded as one of the nation's experts on stalkers, particularly those who threaten celebrities.
"Celebrity stalkers tend to, as a group, to be much more mentally ill than other stalkers," said Meloy.
Meloy says the average celebrity stalking case lasts about 16 months, but he's seen them go on as long as 15 years.
While the risk of "death by stalker" is relatively low for celebrities, Meloy says the frequency of homicidal celebrity stalking has increased significantly since 1980.
"Violence among celebrity stalkers, if it is carried out, is usually planned and purposeful," he said.
Rebecca Schaeffer, John Lennon and Jill Dando -- murdered
Jerry Lewis, Monica Seles and Theresa Saldana -- stabbed
Michael Landon's stalker killed two security guards
Olivia Newton John's stalker killed five members of his family
PPaula Abdul's and David Letterman's stalkers both committed suicide.
"Their lives are bereft of any normal satisfactions," said Meloy. "Oftentimes they are living alone and have had very unstable work history and have not done well and oftentimes because of the psychiatric disorder, but paradoxically they tend to be brighter than average so you see an ability to manipulate that is better than average criminal behavior."
One stalker, considered to be extremely dangerous by both Meloy and LAPD, was Jonathan Norman.
"Mr. Norman had a plan to kidnap Steven Spielberg and to sexually assault Steven Spielberg," said Dunn. "We deal with delusional people all the time with celebrity cases. … But when they start acting on their impulses, as Jonathan Norman did with Steven Spielberg and they start trying to put a plan into action, that's when the hairs on the back of your neck have to stand up."
Investigators say Norman tried to pass himself off as Spielberg's adopted son, but his journal entries later revealed a darker obsession with the Hollywood icon.
"We pulled some of the pages from his handwritten notes and what's clear here is the planning," said Meloy, reading parts of Norman's entries.
"I would force him to put on a screening muzzle," Norman wrote, "and then put handcuffs on him with his hands in front of him I would then have him direct me to his apartment and then cuff and gag any roommates he might have."
But it didn't stop there. Norman had a shopping list.
"He is going to have eye masks, three cuffs, four pairs of nipple clippers, dog collars, check for nipple shockers," said Meloy as he read from Norman's own lists that were eventually used as evidence in the case. "Three locks with same key and again, you see both the level of aggression and sexual aggression that Norman thought about and likely fantasized about as part of his attack on Spielberg."
Norman was sentenced to 25 years to life for his crimes. But even when the threats don't reach this level, celebrities often live in fear.
TV and film star Morgan Fairchild once played the role of a stalking victim in the movie "The Seduction." And with the help of the LAPD stalking unit, Fairchild recently broke free of an obsessed woman.
"Different people who have had females stalkers who you tend to view as less threatening, in a certain kind of way, but they can absolutely be as lethal," said Fairchild.
The woman fixated on Fairchild believed the actress believed Fairchild was her mother and was making very personal contact, sending letters addressed to her home.
"It's not fun," Fairchild said. "Especially this day and age with the technology that is readily available to any weirdo on the street. You do get a little concerned about your safety and security."
What began as innocent postings on her Web site ended with cards, gifts, photos and handwritten letters that the LAPD says escalated its level of concern.
"I'm going to show up on your doorstep," Fairchild recalled the letters saying. "I'm going to fly across the country. You promised me you were going to pay all our bills and you haven't done it and now I'm hungry. So it was getting threatening."
Meloy says it's common for stalkers to believe they're somehow related to the celebrity. Experts say Robert Hoskins, one of the most dangerous on record, the man who scaled the security walls of Madonna's estate, tried to get to the singer, whom he believed was his wife, and was ultimately shot by her bodyguard.
"The thing that makes Hoskins so dangerous is … he believes [that] Madonna's spirit can inhabit anyone at any given time," said Dunn. "So if Robert Hoskins was walking the streets today and he decided that you or I were Madonna, we would be at grave risk. Very dangerous person. We've got to keep this guy in custody for as long as we can."
Meloy also says that celebrity magazines can play a role in making celebrities more appealing to stalkers.
"The more the magazines humanize the celebrity figure and point to their vulnerabilities and characterize them in emotional ways," said Meloy. "It can reduce the space between the celebrity and the stalker. Their personal space begins to vanish or evaporate."