1. Beatles frontman John Lennon died at 40 after he was shot in the back four times outside his New York City home on Monday, December 8, 1980 by Mark David Chapman, an obsessed fan who’d become the poster boy for deranged celebrity stalkers.

2. Up-and-coming actress Rebecca Schaeffer (My Sister Sam) was shot and killed in 1989 at the front door of her L.A. apartment by stalker Robert John Bardo, who’d hired a private detective to gain her personal info. The next year, California passed the first anti-stalking law.

3. Paula Abdul’s stalker Paula Goodspeed — a former American Idol hopeful — killed herself via pill overdose outside the star’s L.A. mansion in November 2008. In her 2006 Idol tryout, Goodspeed told Ryan Seacrest “I really like Paula Abdul a lot … I’m a really big fan. I make life-size drawings of Paula.”

4. It’s not just Jay Leno that has a history of lurking over Conan O’Brien’s shoulder: In 2008, Boston priest David Ajemian pleaded guilty to disorderly conduct after sending letters to the red-headed comic’s business and home, and even tried to break into a taping of his then-N.Y. based show.

5. ESPN reporter Erin Andrews was famously stalked — and taped — by Michael David Barrett, an insurance salesman who checked into hotel rooms next to hers, and taped the beauty undressing through a peephole. He was sentenced to 2 1/2 years in prison for his transgressions. Andrews was able to parlay the notoriety and public sympathy into a stint on Dancing With The Stars.

6. Dancing With The Stars spring 2009 champion, Olympian Shawn Johnson had a scary brush after her stalker, Robert O’ Ryan, broke onto the set she was filming the dance competition at. A subsequent police search revealed two loaded guns, a knife and love letters addressed to the young athlete. He was subsequently sentenced to five years in a mental hospital.

7. Karen McNeil testified in court she thought she was destined to be Justin Timberlake’s bride, but the My Love singer didn’t feel the same way: in November 2009, Timberlake was granted a three-year restraining order after McNeil trespassed onto his property and broke into his L.A. home.

8. Being America’s Sweetheart hasn’t come without unwelcome attention for Sandra Bullock: The Oscar-winning actress has had to seek court protection from a number of stalkers including Thomas James Weldon, who sent her hundreds of e-mails, faxes and phone messages; and Marcia Valentine left “weird signs” using palm fronds and “pieces of animal fur” for her. Whatever happened to fan clubs?

9. John Hinckley Jr. was so obsessed with Jodie Foster in 1980, he added a special twist to the usual love letter synonymous with stalkers: he famously tried to assassinate then- President Ronald Reagan to impress her. Found not guilty by reason of insanity, the inept assassin has been institutionalized for the past three decades and counting.

10. David Letterman’s longtime stalker Margaret Mary Ray killed herself in 1998, after years in which she tormented the late night host with stunts like stealing his Porsche, threatening him and breaking into his house.