Barely a decade ago the word "virtual" was harmless. It meant "almost", as in "the job is virtually done".
Since the development of social networking, especially Facebook, which in January reported the active membership of almost one in 10 human beings, it has developed a wider application: virtual is the word applied to something that exists online rather than in the real world.
The phrase "virtual life" conjures up playful connotations of interaction with a new community of friends who may, but quite possibly do not, know you in real life.
There is room for make-believe, fantasy and fun. But there is also room for deceit, manipulation and wilful destruction.
The latter possibility has been brought forcefully home in recent weeks with the case of "Facebook predator" Natalia Burgess, who is under police investigation after luring dozens of teenagers and young men into a web of online deceit.
As we report this morning, Burgess is now at last getting the professional care she so obviously needs. But her victims and their supporters now constitute an online, "virtual" lynch mob.
Their reaction is understandable since many of them speak for people who have attempted suicide - one, tragically, succeeded - after communicating with Facebook "friends", who were actually personas created by Burgess. But there is a wider point at issue and bigger lessons to be learned.
Police have attracted some criticism - not all of it unjustified - for being slow off the mark when allegations about Burgess were brought to them. But to be fair the situation is one that the law, which police are charged with upholding, has yet to come to terms with.
Many, if not most, of our children will spend their working lives doing jobs that don't yet exist because they haven't been invented.
It is this technology-driven change, and behaviour, that society may find objectionable or even monstrous, but when such behaviour is still in the process of being defined, we are some way from groping with its moral and ethical implications, and further still from developing criminal and civil codes to regulate it.
As one policeman dealing with the Burgess case remarked to our reporter this week, "there is no law against telling porkies".
Charges that are being considered, among them fraud and misuse of a computer, plainly do not go to the heart of the damage that can be - and allegedly has been - done.
To their credit, the police have joined forces with the independent non-profit group NetSafe to explore ways of using this specific case as an educational tool to raise awareness among teenagers and young people about the dangers that can lurk in the cyberworld.
But, while authorities grapple with the big picture, the responsibilities for looking after the vulnerable at an individual level must remain with families and loved ones.
And if the Burgess case shows us anything, it is that the familiar strategies of the recent past are already out of date. The idea that keeping the family computer in a common area would allow parents to monitor their children's activities has been rendered redundant by laptop technology and internet-connected cellphones (Burgess does not own a computer).
The potential upside of what has gone on is that it could renew parents' resolve to keep in touch with their kids' hopes and fears by cultivating real - not virtual - relationships with them.