Perhaps as strange and unsettling as the 19-year-old Biggs' invitation last week is the lengthy record of the discussion among the dozens of virtual onlookers who accepted it.

Abraham Biggs Jr. announced his intention to overdose on pharmaceuticals to members of an online discussion board to which he'd been frequently contributing for two years. And then he invited users to watch. "Ask a guy who is gonna OD (again) tonight anything," he wrote, adding a link to a live video feed from his bedroom webcam.

Perhaps as strange and unsettling as the 19-year-old Biggs' invitation last week is the lengthy record of the discussion among the dozens of virtual onlookers who accepted it. What many of them saw was a view of Biggs curled up on his bed for most of the night — moving little if at all.

Biggs' choice to broadcast himself to a crowd of viewers was in some sense the virtual equivalent of stepping out onto the ledge of a building. In this case, no one materialized to talk the Floridian teenager down, and we can't know if one well-timed 911 call would have saved his life. But it may be that more to blame than the witnesses is the distance — both emotional and physical — that is always there between those who interact online.

The culture-shifting properties of online video are well known: Anyone can broadcast, at very low cost, without leaving their home, and to an audience whose size has no built-in limit. Biggs, who was an active user of the live streaming service Justin.tv, would have been no stranger to the medium's advantages. But perhaps more than the Web's promise of easy publicity, said Dr. Jay Nagdimon, a former director of the Suicide Prevention Center, Biggs may have felt "a kind of a psychological longing to be with other people, to feel important, to feel cared about," he continued. "Maybe there was some part of him that hoped someone would say something to make him change his mind."

The few responses Biggs got before he crawled finally into bed showed that the crowd he'd attracted was less than sympathetic.

"Oh, not again," wrote one forum member, alluding to previous instances when Biggs had discussed plans to overdose. "He keeps failing."

"If you really wanted to die, you'd be approaching this very differently," wrote another.

"People who commit suicide go to hell," wrote a third.

Nagdimon noted that challenging the seriousness of a person threatening suicide is "the last thing you want to do," and, indeed, for hours after Biggs went to sleep, and even after viewers woke up the next morning to see Biggs lying in the same position, the blithe attitude of many commenters remained unchanged.

Bodybuilding.com has removed the thread I'm quoting from, but I was able to save the first 10 pages of posts — about 300 of them. This record is an eerie chronicle showing the conflict among the concerned, the skeptics and the downright cruel. But those with an impulse to help remained the minority for too long: According to time stamps on the forum posts, members did not begin calling the police until nearly 10 hours after Biggs reported taking the pills.

We know that, in some cases, when real-life crowds witness a crime, the individual members may be less likely to react, a phenomenon psychologists refer to as "diffusion of responsibility." In common-sense terms, it's the feeling that someone else might step up to handle the situation — someone better equipped than you.

And if that's a problem in a crowd of people standing on the same subway train, you can imagine it might be even worse on the Internet, where the onlookers are not only separated from the event by distance, but are themselves dislocated from, and invisible to, one another.

Dr. Kaveri Subrahmanyam, a psychologist at California State University, Los Angeles, who studies the way young people interact with digital media, wrote in an e-mail that the Biggs case might be an instance of "the Internet's inhibitory effect on one's moral compass."

In describing what she called the "darker parts of the Internet," Subrahmanyam pointed to a kind of trifecta of anonymity: people with hidden identities, who are not physically present, but are nonetheless gathered in a virtual crowd. In other words, a disembodied mob of faceless people. Sounds like some kind of nightmare.

Still, Subrahmanyam noted, in the case of Biggs, "just the opposite could have happened, where one person would've stood up and told him not to do it, and the rest followed."

There are instances of Web crowds coming swiftly to someone's aid. In 2005, Bev Holzrichter of Charlotte, Iowa, was kicked by one of her horses that had just given birth and her right leg was severely injured, said reports at the time. There was a webcam in the stable, and because it was foaling season, people from around the world were watching, and the local rescue unit was flooded with calls from different countries.

E-mail sarno at david.sarno@latimes.com.