When you become famous, you not only have to prepare for never-ending paparazzi flashes and mobs of fans, but you must also brace yourself as you enter the world of extreme fandom. With all the glitz and glam can come a whole lot of devotion, as people like Britney Spears, Justin Bieber and Miley Cyrus have learned all too well.

Sometimes, a fan is so dedicated to a celeb, they go to extreme measures to meet them. And then, there are much more tragic and terrifying incidents, like the death of Selena, or the guys who wanted to do serious physical harm to Justin.

Read more about the most intense celebrity stalking experiences in the list below.

  • Lana Del Rey

    Stalker: Zachary Self
    Pascal Le Segretain, Getty Images/ Johnson County Detention Center

    The guy stalking Lana Del Rey in 2015 swore that his obsession started after he took hallucinogens. Construction workers found Zachary Self lying on a mat in the garage of Lana's Malibu home. The then 19-year-old made a run for it but was soon apprehended by police after finding numerous obsessed love notes to the singer as well as a court citation that happened in Kansas.

    Self, whose family claimed that he was bipolar, pleaded no contest to stalking. He spent 84 days in jail, was on probation for five years and had to be put into a residential program. Finally, he has to stay away from her for the next decade.

  • Beyonce

    Stalker: Bassey Essien
    Jason Merritt, Getty Images

    Beyonce stalker Bassey Essien convinced himself that the real Bey had been killed by an impostor Beyonce who was living the pop star's life. Ooookay...

    Essien sent Bey threatening letters back in 2009, probably claiming to out her as a fraud. When the diva performed in London at the Sound of Change concert, Bey's security detail was briefed on this guy to make sure he was no where near the singer.

  • Britney Spears

    Stalker: Masahiko Shizawa
    Frazer Harrison, Getty Images / Facebook

    The story of Britney Spears and Masahiko Shizawa, the man who was stalking her in 2002, is definitely a weird one.

    It all started when the Japan native, who was said to be madly in love with Brit, began sending Spears love letters, e-mails and pictures of himself along with messages like "I'm chasing you." A restraining order was issued, but Shizawa still stalked Brit outside two of her houses as well as her parents' home, trying to gain entry wherever he could.

    Then, in an odd turn of events, Shizawa ended up trying to sue Spears after a confrontation ensued with her bodyguards outside of her house. He claimed he suffered "extreme emotional stress" after one of Brit's protectors pointed a gun at the man. However, the case was quickly dismissed.

  • Miley Cyrus

    Stalker: Jason Luis Rivera
    PacificCoastNews.com (2)

    "I am friends with Miley Cyrus….She’s my wife. Me and Miley have been friends for five years," is reportedly what Miley Cyrus' stalker, Jason Luis Rivera, told police when he was caught trying to get into the 'We Can't Stop' pop star's house with a pair of scissors.

    Cyrus got a permanent restraining order on this guy before Rivera was convicted of misdemeanor trespassing and sentenced to 18 months in jail.

  • Justin Timberlake

    Stalker: Karen McNeil
    Jason Merritt, Getty Images / Tumblr

    The woman who was stalking Justin Timberlake back in 2009 is seriously cuckoo.

    Karen McNeil, pictured above, showed up at Timberlake's house in November of '09 claiming that she was God, and that she and the 'SexyBack' crooner were destined to rule together. She also said that "Babylon witches" were after her and she feared they were going to cast an evil spell on her. Of course, authorities promptly took her to a psychiatric facility.

    This was not the first time McNeil showed up to JT's L.A. home either. Timberlake said she had gotten through the gates before, and that she claimed to know him.

    Prior to stalking the 'Suit & Tie' singer, McNeil was obsessed with Guns N' Roses frontman, Axl Rose, and was arrested several times outside of his home.

  • Selena Gomez

    Stalker: Thomas Brodnicki
    Andreas Rentz, Getty Images / TMZ via YouTube

    Creep alert. Selena Gomez had one giant scare in early 2012, when a man by the name of Thomas Brodnicki claimed he had "over fifty conversations with God a day, about killing Ms. Gomez."

    In an even stranger turn of events, Brodnicki himself urged Gomez to file a restraining order. In a statement, he said, "I believe that a restraining order should be issued against me to prevent me from trying to contact Selena Gomez. I do not wish to object to the restraining order against me because I know it is the only thing that will make me stay away from Selena." Um, WHAT?

    Gomez heeded her stalker's warning, and was granted a a three-year restraining order against Brodnicki in Jan. 2012.

  • Madonna

    Stalker: Robert Dewey Hoskins
    Dimitrios Kambouris, Getty Images / POO/ AFP / Getty Images

    In 2012, Madonna was in fear for her life for the second time, as the man who was convicted of stalking her in the '90s escaped the mental institution where he was committed.

    Robert Dewey Hoskins was deemed a huge threat and was first sentenced to 10 years in prison for stalking Madge in 1996. He had been obsessed with the Material Girl for years, and her bodyguards were forced to shoot him when he hopped the fence at her Hollywood Hills home. Hoskins was a violent man and had said he was either going to marry Madonna or "slash her throat from ear to ear."

    Hoskins served his time and was later transferred to a psychiatric hospital after another arrest, but he escaped from the facility in early 2012. He was apprehended by police in February, and taken back to the Metropolitan State Hospital in Norwalk, Calif.

  • Paula Abdul

    Stalker: Paula Goodspeed
    Cindy Ord, Getty Images / YouTube

    Paula Abdul's stalker story is one of the more traumatizing on this list. A former 'American Idol' contestant, Paula Goodspeed, was absolutely obsessed with the 'Straight Up' singer, and even auditioned for the show to no avail.

    However, what seemed like fanatical yet pretty harmless behavior -- for example, her car was totally decked out with everything Paula, from her "ABL LV" license plate to the pic of Paula on her rearview -- was obviously much more. One day in Nov. 2008, Goodspeed was found dead in her car outside of Paula's home due to an overdose on prescription drugs. The death was ruled a suicide.

    In a statement, the singer/choreographer said, "I am deeply shocked and saddened at what transpired yesterday. My heart and prayers go out to her family."

  • Justin Bieber

    Stalkers: Dana Martin, Mark Staake and Tanner Ruane
    Mike Ehrmann, Getty Images / PacificCoastNews.com (2)

    Justin Bieber has a lot of fans, but a few of them took their love for the 'All Around the World' pop star a little too far.

    Dana Martin was doing a life bid in a New Mexico prison for the brutal rape and murder of a 15-year-old girl. He contracted his prison buddy, Mark Staake, and Staake's nephew, Tanner Ruane, to have them find Bieber and castrate him with garden shears so he could have his, uh, "parts" as a souvenir.

    Martin admitted he was attracted to Justin saying, "He's a good-looking kid. Would I go to bed with him? Yeah. He's legal, so probably."

    Martin's hit men (Staake and Ruane, pictured above) were arrested after police found out about their vicious plot, which was definitely a good thing for Bieber...

  • Joss Stone

    Stalkers: Junior Bradshaw and Kevin Liverpool
    Devon and Cornwall Police Department / PacificCoastNews.com

    Joss Stone had some seriously scary stalkers back in 2011. Two men were accused of plotting to rob and kill the songstress. Their plan was to decapitate the singer, dump her body in a river and apparently make off with some cash and other loot in the process.

    Bradshaw and Liverpool were found at Stone's home in possession of a samurai sword, hammers, knives and a body bag. Liverpool was sentenced to 18 years in prison for the murder plot, but Bradshaw's sentencing

    was delayed pending a psychiatric evaluation.

    We're just glad Joss Stone made it out okay!

  • Selena

    Stalker: Yolanda Saldivar
    Tumblr (2)

    Selena Quintanilla-Pérez's tragic death offers a prime example of the worst case stalker scenario.

    Yolanda Saldivar ran Selena's fan club as well as a clothing boutique for the singer, but people quickly began to notice that she obsessed over the songstress. She had what would be considered a shrine to the singer in her home, complete with posters, candles and videos.

    Finally, after Saldivar began embezzling money from Selena's fan club, the 'Dreaming of You' singer cut ties with her, and that's when things got really ugly. Selena met with Saldivar to retrieve essential tax documents on March 31, 1995, and this is when the former employee shot and killed Selena. Saldivar was found guilty of murder and sentenced to life in prison. She is eligible for parole in 2025.

  • Kylie Jenner

    Stalker: Name Unknown
    Larry Busacca, Getty Images

    Kylie Jenner had a frequent unwelcomed visitor up until mid-June 2016. Apparently, a man attempted to break into The Oaks -- the gated community where Kylie and her Khloe and Rob Kardashian live in June 2016. The unidentified man tried to tell security that he had a meeting with Kylie. However when they refused him entry, he drove into the gate, cracked it and then sped away. But he didn't give up and attempted the same thing two weeks later. Security cameras got a shot of his license plate and informed police. Now Kylie's house is on the market.