"Open house parties" were around when I was in high school - but our Bacchanalian gatherings, where teenagers indulged in dancing, snogging, drinking, smoking marijuana, raiding refrigerators and a lot of angst, were contained within the confines of about 100 kids. Today, Facebook has exploded that model, providing the perfect proof for the six degrees of separation theory: we are only six steps away, by way of introduction, from anyone on earth. It sounds cosily "inclusive", the global village politicians keep telling us we live in. But do we really want these global villagers in our living room?
After all "a friend of a friend" is not necessarily a friend at all. The online post that asks, "Hi, can I come along to your party?", accompanied by a smiling photo and a credible profile (good school, familiar-sounding friends, heart-warming hobbies) may sound innocuous, both to the Luddite parent who doesn't know Facebook from Twitter, and to the unsuspecting youngster.
I know children who learn about "stranger danger" before they can fit two Lego pieces together; and parents in the playground who rush over when an unknown man draws too close to their little treasure. Yet alarm bells don't go off when an approach is made, or an invitation posted, on a social networking site.
They should. Jay Whiston's Facebook party experience was horrific, but it's not isolated. A 23-year-old student fell to his death after a giant cocktail party, organised through the site, drew a crowd of over 20,000 in France two years ago. Earlier this year in Aberdeen, 15-year-old Amy Louise Manson posted an invitation to a party on Facebook. It drew gatecrashers who wrecked her family home, leaving holes in the walls and stains across the floors. Rebecca Javeleau, 14, from Hertfordshire, mistakenly made her address and phone number visible on Facebook while publicising her birthday party in 2010; she ended up with 21,000 people RSVPing yes. Unsurprisingly, the party was cancelled and the family had to call the police to surround the house and prevent chaos.
My friend Helen wasn't so lucky. When she flew to Hong Kong on business, she was woken in the middle of the night by a phone call from her tearful nanny. Between sobs, she explained that her charges - Helen's teenage sons - had thrown a party in Helen's garden square, after advertising it on Facebook. Hundreds of youngsters, barely any of them known by Helen's children, had turned up. Neighbours had called the police… and now were calling for my friend's head on a platter.
Yet what is a parent to do? Facebook is part of our children's world. Our boys are on it for hours every day. Like many parents, I worry that the site is not only dangerous, but that it is a distraction. However, banning it would be as pointless as banning smoking: in the same way the 19-year-old will climb out onto the roof and sneak a fag, a ban on Facebook will drive the addict to subterfuge.
Monitoring Facebook is equally tricky. Some children may "de-friend" tech-savvy parents, removing them from their online sphere. Others are more devious. I know of one father who thinks he is "on top" of what his daughters get up to, and boasts of their innocent after-school activities: it's all pony club and Brownies. In fact, the girls have two Facebook pages - one that they dutifully write up for Daddy's benefit, and one for their pals.
The only weapon we parents wield is information. Getting to know Facebook and Twitter has put us on our guard, and has demonstrated to our children that we are not cut off from their world.
We've learnt, for instance, that users can opt for a privacy setting, ranging from allowing posts to be read by everyone, to allowing access only to a highly customised group of proper "friends". Facebook has had to make these security steps easier to manage after concerned parents complained.
We've learnt, too, to take Facebook seriously. The prospect of a soulmate at the click of a button may not convince many grown-ups, but that's quite a turn on for a teenager. Many young people, tongue-tied and insecure, feel intoxicated by their ability to type a few words that will reach millions. They may not fit in at school, but through Facebook they belong to a huge circle of friends. At their age, I, too, would have loved it.
If I've learnt that I can't control what my children get up to on Facebook, I know that I can set ground-rules for parties at home. When we go off later this week to a conference in France, our sons will be left in charge. In a sentence, boys: don't even think about it.
