Several high-profile cases involving people who met playing online games have led experts to caution that such Web sites have a unique environment that could be a breeding ground for criminal minds.
— A 2-year-old girl nicknamed "Baby Grace" by detectives was found dead in October in a locked box in Texas — allegedly the victim of a beating murder at the hands of her stepfather and teenaged mother, who met playing the online fantasy game "World of Warcraft."
— A 31-year-old Australian woman named Tamara Broome was nabbed in June when she traveled to North Carolina to lure a 16-year-old boy she encountered playing the same popular Internet game.
— Twenty-six-year-old Florida resident Daniel Lenz is also under investigation for allegedly coaxing a 15-year-old girl he played "World of Warcraft" with to run away with him.
— In China, a "Legend of Mir III" player is spending the rest of his life behind bars for fatally stabbing another for the "theft" of a virtual sword.
Massively multiplayer online games — or MMOGs, as they're called — can foster more vulnerability than there might be on other virtual meeting spaces such as dating and social networking sites, where participants are inclined to be on the lookout for suspicious behavior from the start.
"When you're in a social situation like that — playing a game, having fun — you're comfortable with the people you're playing with," said cyber-stalking victim Jayne Hitchcock, president of Working to Halt Online Abuse (WHOA). "People are just not very careful. They lose all sense of reality and themselves."
Such conditions can lead participants to be more trusting of each other and less cautious. Players tend to be focused not on meeting each other, finding a love connection or promoting themselves, but on getting through the game, working as a team and concocting strategies to win. The pressure to make a good impression and project a certain persona is off.
Since teammates typically don't compete using their own identities but instead take on characters called avatars, they frequently feel safer and less exposed than they might if they were putting up personal profiles on sites like MySpace, Facebook and Match.com.
"You're hiding behind a cloak of anonymity and false pretenses," said University of Baltimore criminologist Jeffrey Ian Ross. "They force you to pick an alter ego."
Ross said that because defenses are down, people can be more susceptible to the advances of predators or those who are mentally unstable.
But it isn't just the social-lubricant aspect of the hobby that is cause for concern.
The common goal of annihilating the foe can bring out a belligerence that sometimes spills over into real-world interactions, especially within those who become addicted to what they're playing, said Robert McCrie, a professor in the law and police science department at John Jay College of Criminal Justice in New York.
"You observe people playing these games — it draws out a kind of aggressiveness and competitiveness in their behavior," he said. "There is a concern for people who become obsessively involved with cyber gaming."
While there are some who believe that real-life dangers lurk in the virtual gaming world, others say that just the opposite is true because the games are complex, requiring smarts and quick, sharp thinking.
"The majority of people who play these games don't fall victim to this sort of thing," said Ross. "They're either savvy, or they're very rule-bound."
Furthermore, most of those who participate are primarily interested in devising ways to advance, defeat the enemy and win, not prey on unsuspecting fellow gamers.
"The goal is not specifically to meet friends but to play a game," said Michael Goodman, a director at digital entertainment research firm Yankee Group. "I would argue that it is a little more difficult to mislead. You know coming in that the person is not who that character is. You know the person on the other side is not an elf."
Researchers are taking a closer look at a variety of relationships formed on multiplayer game sites, and with good reason.
About 25 to 30 million people worldwide now play MMO games, according to Yankee Group. As many as 7 to 9 million of them are in the United States. And as with other types of popular cyber-meeting spots, the incidents of friendship, dating and even marriages that result are on the rise.
Research gathered by Stanford University Ph.D. Nick Yee, an online gaming expert, found that in 2006 about 29 percent of female players ages 12 and up and 8 percent of males in the same age range reported dating someone they met in the virtual world of multiplayer Internet games. That's compared to 18 percent of women and 6 percent of men dating fellow gamers in 2003.
Yee used survey data collected from "EverQuest," "Dark Age of Camelot" and "Ultima Online." The findings are particularly significant because only one-third of players are single to begin with.
Sony Online Entertainment said last year that at least 20 couples have married after meeting as players of its "EverQuest" fantasy game series.
At least 20 weddings have happened between pairs who met playing another favorite called "Anarchy Online," according to its Norway-based creator, Funcom NV.
But some hook-ups have had deadly consequences.
In the case of toddler "Baby Grace," whose real name was Riley Ann Sawyers, her mother Kimberly Dawn Trenor met second husband Royce Clyde Zeigler II playing "World of Warcraft."
Trenor, 19, had had a volatile relationship with Riley's birth father and wound up moving from Ohio to Texas to be with Zeigler, 24.
Zeigler and Trenor abused the toddler, according to court documents, and Trenor told police that one July day, they beat, tortured and threw the child across the room, killing her. They allegedly concealed her body in a box in a shed and then tossed it into Galveston Bay.
In the Lenz and Broome cases earlier this year, both adults allegedly struck up relationships with teenagers playing "Warcraft" and then convinced them to meet in person before authorities caught on.
Representatives for Blizzard Entertainment, which produces "World of Warcraft," did not respond to requests from FOXNews.com for comment.
The 2005 Chinese murder of "Legend of Mir III" player Zhu Caoyuan by teammate Qui Chengwei happened after Zhu's game character sold a virtual sword loaned to him by Qui to another player.
Qui went to police about the "theft," but his reports were ignored because no real weapon was stolen. An enraged Qui broke into Zhu's home and fatally stabbed him in the chest with an actual knife.
There have been other cases involving online gaming that captured media attention.
In 2005, the baby of a South Korean couple suffocated when they left the child alone to play "Warcraft" at an Internet cafe. A Wisconsin boy named Shawn Woolley died in 2002 of an apparent suicide in front of his computer because he was rejected by a fellow "EverQuest" player.
"People have electronic hookups that sometimes lead to disappointing ends," said McCrie. "While I believe that it doesn't happen a lot, the likelihood for there to be a disconnect between two parties is greater if their connection comes over cyberspace rather than over a table. When we meet in a public, we're able to assess that individual's signals more accurately."
Still, the majority of close encounters of the gaming kind don't end badly, according to criminologists.
"The issue of suicide and murder is an anomaly," Ross said. "Yes, there are people on these games who have evil intent. ... But it's highly unusual. That's what makes it so fascinating."
For law enforcement, prosecuting cyber-based crimes of any sort is seen as an ever-growing challenge.
Authorities in Missouri announced last week that there was not enough evidence to charge those involved in the suicide of 13-year-old Megan Meier, who hanged herself after being jilted on MySpace by an adult she thought was a teenage boy.
At the time of the incident, there was no Missouri cyber-bullying law, though Meier's hometown has subsequently passed a measure making the crime a misdemeanor.
Despite some experts' theories that the gaming community is subject to its own set of circumstances, law enforcement doesn't see it that way.
Even when virtual player relationships do result in crimes or violence, the FBI says investigators wouldn't necessarily take a special approach to such cases.
"If something like that came into us, I don't know that we would treat it any differently than any other kind of Internet crime," said New York FBI Special Agent Barbara Daly.
Yankee Group's Goodman agrees, saying that cyber game-related tragedies are no different from or more common than those that originate from any other online meeting.
"Games and gamers are a microcosm of society. There's good people and bad people who are playing them," he said. "The same things we see manifesting themselves on MySpace and Facebook we see manifesting themselves in online games as well."
It remains to be seen whether online game-related violence will flourish as the number of players continues to grow — and the popularity of digital entertainment rises.
And while it might be a stretch to liken the Web to a modern-day Pandora's box, the analogy does hold some water.
"You're going to see a lot more of these stories, unfortunately," predicted WHOA's Hitchcock. "Nothing surprises me anymore in terms of the ways the Internet can be used to harm people."