1. Philip Markoff
Dubbed the "Craigslist Killer," he was a medical student in Boston who met his victims via Craigslist's erotic services. He committed suicide in August, 2010, while in jail waiting to be tried for the murder of Julissa Brisman.
2. John E. Robinson, Sr.
Robinson, a grandfather, was convicted in 2003 after a murder spree that lasted 15 years and included the murders of at least eight women. He met several of his victims in chat rooms, and has been dubbed "The Internet's First Serial Killer."
3. Michael John Anderson
The first to be called a "Craigslist Killer," Anderson met his victim Katherine Ann Olson after luring to his house with an ad looking for nanny services. He was 19 at the time of the murder in 2007. He was convicted of murder in 2009.
4. Hiroshi Maeue
Maeue was given the name "Suicide Website Murderer" in Japan after trolling for victims to strangle on Japanese online suicide clubs. He killed three victims over four months.
5. Armin Meiwes
Meiwes is the German who met a man over the internet who agree to let him kill and eat him. Miewes videotaped the entire grisly affair, and was eventually arrested and sentenced to eight years in jail for manslaughter, ostensibly because his victim, Jürgen Brandes, agreed to the killing.
6. John Katehis
Another Craigslist Killer, Katehis allegedly murdered radio reporter George Weber in 2009 after responding to Weber's Craigslist ad for "rough sex." Katehis, just 16 when he was arrested, is accused of stabbing Weber 50 times.
7. Robert Frederick Glass
Glass is sort of the Armin Meiwes of the U.S. In 1996, he met, tortured and strangled Sharon Lopatka in an act of consenual homicide after meeting her via the internet. Glass was convicted of voluntary manslaughter, and died of a heart attack in jail.
8. Lisa M. Montgomery
In 2004, Montgomery murdered the pregnant Bobbie Jo Stinnett and removed and stole her baby. She'd found Stinnett in a rat terrier chatroom. The baby survived, and Montgomery was caught and is currently on death row at a federal prison in Texas.
9. Christian Grotheer
Meet Germany's "first internet murderer." Using online dating sites, Grotheer met over 100 women and murdered two of them. In fact, during his trial, he wanted the court to consider the fact that "except for these two, all the other 98 are still alive," so he shouldn't be considered a serial killer.