The Virtual Revolution BBC2

FACEBOOK is the world's largest social network – even bigger than the Women's Institute.

It has 350 million users, posting such fascinating comments as "Just discovered I can bite my toenails!", "No cake – boo hoo!", and "Who thinks Prince Harry's sexy?".

I really must stop checking Fergie's message page.

According to presenter of The Virtual Revolution, Dr Aleks Krotoski, pictured above, a stern looking woman who found her hairdresser at lastminute.com, if Facebook was a country it would have the third biggest population in the world. Look out for it in the medal table at London 2012.

"In the past," she opined, "groups have been constrained by geography and history, and this is not necessarily the best way for them to be organised.

"You want to be in groups of individuals you have something in common with."

Krotoski ignores the fact that we've had places like that for centuries – tea shops, for example, and prisons.

On she wittered about "a portable homeland, replacing the border of a country and linking people as though they all live in one place".

"If you live in an area where there's no like-minded people," she said, "you can go on the web and meet them."

Except, of course, you can't.

The fact is that Binty from Bridlington, who you've befriended on that Linens Of Yesteryear chatboard, is in fact Dennis from Doncaster.

He's going to extract your information then come round and pinch your tablecloth.

Then there's Twitter, which, at just four-years-old, is another global phenomenon, allowing users to send a message, known as a tweet, 140 characters long, to others.

"When it began," said Stephen Fry, one of the best known Twitterers, "it seemed like something for geeks. It was inconsequential prattle."

And the difference is now?

"Can you imagine how quickly the Berlin Wall would have fallen if Twitter had existed?" asked Fry.

I expect it'd still be there. People would have been too busy at home tweeting to head out with a sledgehammer.

"In the 20th century," said one expert, "if you had something to say in public and you weren't a media professional, you couldn't.

"People who went out of their way to get their message out there by popular channels, like holding signs by the roadside, were widely thought to be off their rockers."

They're still off their rockers. Except now they're on the internet.

"Does anyone have the power to turn the internet off?" asked Aleks. It seems not.

Heaven forbid – we might have to start talking to each other.