Being a celebrity of course comes with tons of attention from adoring fans, but occasionally some fans take it too far and cross the line from adoration to obsession.

Several celebrities have had their fair share of stalkers over the years, and some have not only had to file criminal charges, but have potentially had their lives threatened as a result.

As Alec Baldwin is currently preparing to testify in the case of a Canadian actress who is accused of stalking him, Enstars has compiled a list of other celebrities who have had very scary situations with stalkers that could have very well harmed them.

1. Gwyneth Paltrow: Back in 2000, Dante Michael Siou sent Paltrow five letters a day as well as boxes of porn. After showing up unannounced at her parents' home and sending the actress a vibrator, saying he "loved her," he was declared legally insane and hospitalized in California.

2. Catherine Zeta-Jones/ Michael Douglas: Dawnette Knight was sentenced to three years in prison in 2004 after she sent letters to Zeta-Jones stating that if she didn't leave her husband, Knight would have cut her into pieces and fed her to her dogs.

3. Shawn Johnson: In 2009, when the Olympic gold medalist, then just 18, was competing on ABC's Dancing With the Stars, she was put through an ordeal when 36-year-old Robert O'Ryan jumped a fence at the studios to get to Johnson. His car, which was searched after his arrest turned up full of duct tape, plastic ties, a bulletproof vest and several weapons. She later testified at his trial and O'Ryan was convicted of felony and burglary stalking charges and two misdemeanor concealed weapons violations.

4. Selena Gomez: In 2011, 46-year-old Thomas Brodnicki became so infatuated with the 20-year-old Gomez that he reportedly spoke to a therapist about conversations with God where he would need to kill her. When Gomez attempted to get a restraining order against him it was almost denied until he himself showed up at court and admitted he was a threat, saying "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."

5. Taylor Swift: In April 2013, 22-year-old Lucas Vorsteveld was arrested for trespassing on the country singer's newly purchased $17.75 million property in the coastal town of Watch Hill, R.I. Vorsteveld admitted that he was trespassing, but claimed he hadn't intended to get near the country singer.  Vorsteveld was ordered to stay away from the singer's home, but will have the protective order expunged from his record if he stays out of trouble for the next year.

6. Jennifer Lopez: Lopez had a protective order against John Dubis in early 2013 when he contacted her mother, but that didn't stop him from trying to get in contact with the recording star again. He was actually arrested in August for burglary, stalking and criminal contempt after he was found to be camping out in the pool house of Lopez's Hamptons N.Y. mansion for six days.