By Patrick Jackson
Some may regard the idea of messaging condolences to someone electronically as inappropriate but to those growing up on Facebook and MySpace it is becoming second nature.
When sudden, violent death visits a college or school as it did at Virginia Tech on 16 April, it can turn social networking sites into channels of breaking news, and transform personal pages into makeshift memorials.
Facebook criticised journalists for violating the privacy of its users' profiles and memorial sites to glean information about the massacre.
Responses to the fatal stabbing of a 13-year-old schoolboy in Vancouver, Canada, this month prompted different concerns.
Among the Facebook memorials was a forum which named and discussed the chief suspect, a juvenile, just as police were withholding details for legal reasons.
Just how private are the personal spaces of the social networking sites when tragedy strikes?
Privacy through obscurity
"This idea that if you set up a memorial site within Facebook it will be private is a bit of a misconception," says Alfred Hermida, journalism professor at the School of Journalism of the University of British Columbia in Vancouver.
journalism professor, University of British Columbia
"A lot of social networking sites like Facebook and MySpace are almost seen by their members as 'their space' but they are actually very public forums," he told the BBC News website.
When Facebook launched three years ago, it was a site only college students could join but it is "now essentially open to anybody with an e-mail account", he notes.
It and other social networking sites are private spaces only as long as their users are not making the news themselves - on the principle of "privacy through obscurity".
"But when something like Virginia Tech happens, you will have information professionals going in to forage and they will find you and you will be propelled into the foreground," Prof Hermida says.
For adolescents, he adds, social networking websites have become "almost like the new playground" but they often fail to appreciate the legal issues involved in an event like the Vancouver stabbing.
"Instead of going to the shopping mall or the gaming arcade they will go online and will say things there as if they are chatting in the playground with friends," he says.
"But once you have written down something online, that actually has legal repercussions beyond just you and your friends on that forum."
Since its launch in March, the website iraqmemorial.org has provided a platform for relatives or loved ones of US soldiers killed in Iraq to talk to camera about their bereavement.
They appear as one-minute talking heads, and their intimate recollections of people killed in action or driven to suicide by their experiences make for both a poignant online memorial and a powerful anti-war message.
In the aftermath of tragedy, going online to leave a tribute, swap messages or blog about your feelings is a positive emotional factor, according to Prof Douglas Davies, director of the death and life studies centre at Durham University.
"In a crisis situation, action is one of the very few things people have as a coping mechanism and in one sense it almost does not matter what the activity is," he told the BBC News website.
But he believes that online messages provide weak triggers for emotional response compared with physical interaction.
"That element which we often see at funerals and memorial services would, I suspect, be absent in the privacy of someone's face-to-face relationship with their monitor," he says.
As author of A Brief History of Death, Prof Davies has noted the progress of mortality though the internet.
director of the death and life studies centre at Durham University
Death, he says, has literally gone online in the form of web cameras installed in crematoria or funeral videos shared with distant relatives in some cultures.
In China, there have been moves to encourage people to remember their dead through internet sites rather than actual grave visits.
Asked if he sees a time when funerals are wholly conducted over the internet, Prof Davies points to the "very clear marginalisation of the dead and of death" in the US, a "society committed to life and living".
"In some parts of America, they have memorial services rather than actual funerals for the majority of people so there is a sense that the coffin is becoming less visible," he says.
However, he does not expect immediate family, at least, to stop attending funerals and cremations simply because "people need people at times of crisis".
"Emotion is as much a product of the social context as it is of the interior, private thoughts of a person, and you need the group to trigger that," he says.
Meanwhile the internet will continue to act as a valuable tool for communicating grief, the professor says, adding:
"In a world where many people's lifestyles are related to the internet it would be natural to expect elements of their death-style to be tied up with the web - otherwise life would be so very fragmented for them."