The story is told of a man who stood, day after day, by the doors of a bank of elevators in a New York skyscraper. Asked why he loitered there for hours on end, he replied simply: 'I wait for people to brush past me - I just need to be touched.'
The story may well be apocryphal but its central theme, urban isolation, will resonate with many Americans as they consider the dramatic tale of three young women released from virtual slavery yesterday.
People across the USA listened with horror on Monday evening to the unfolding story of the three, now aged in their twenties, who had been held captive in an Ohio house for the best part of a decade.
The three women were allegedly kidnapped by three brothers who are now aged in their fifties. The mother of one of the victims died in 2006, heartbroken by the belief that her daughter, though perhaps still alive, might never be found.
Aside from the obvious questions about what motivates men to behave in such inhumane and depraved ways, we should also consider the question of how the neighbours remained unaware of the situation for so long.
News reports emerged today in which people living nearby claimed to have seen naked women in the garden. Other reports spoke of a small child who was seen looking out of an upstairs window during the day, apparently without adult supervision.
It seems, though, that nobody had any inkling of the sinister goings on within the otherwise typical suburban property. As seems often to be the case in these situations, locals described the owner of the house as seeming like just another ordinary member of the community.
This is perhaps what Hannah Arendt meant when, in her writings on the Holocaust, she spoke about the 'banality of evil'.
Doubtless this sorry episode will remind many of the story of Elizabeth Fritzl who was held captive by her father in a four-room basement for twenty-four years. In that time she was raped repeatedly so that she bore him seven children.
She was in her forties when released and opened up to police only when she was assured she would never see her father again.
Generally speaking, Austrians are famously somewhat insular and reticent to get involved in the affairs of others. Yet it would be unfair to characterise the people of the Austrian village as being in any way complicit in the crimes committed by Ms Fritzl's father.
The same can be said of the inhabitants of this particular part of Cleveland.
Yet we must ask why, when our communication technology far outstrips anything available to our forebears, we don't seem to be any better aware of our surroundings. Indeed, in some cases we may be less aware, not least because of the pressures associated with urban growth and our growing engagement with the cybersphere.
Urbanisation is a wave that’s building worldwide. Already 50 percent of the world's population lives in cities. By 2015 most of Africa will be living in urban centres and ten years later, more than 60 percent of Indians will also live in cities. By 2030, the global population of cities will surpass five billion.
This process brings with it unprecedented opportunities. Already, it is estimated that urban enclaves are responsible for one third of the global economy and almost all of its innovation.
This makes sense. New ideas don't emerge from nothing - they occur when people discover and exploit connections between existing ideas and processes. If ideas are going to connect, people must connect. They do that better in cities than in the countryside.
However urbanisation also poses problems. For certain sections of modern societies, urbanisation combined with rapid digitisation - we live more and more of our lives online - is leading to higher levels of loneliness. Urban isolation leaves people feeling alone in a crowd.
This is having a measurable impact on public health in some centres. In a few large but well resourced cities, physical health is, at least in some respects, better than in smaller communities. New Yorkers, for example, apparently suffer less from heart disease than other Americans.
In urban centres like New York, people often live close to their workplaces and the services they use every day. Consequently they walk almost everywhere, which produces obvious cardiovascular benefits and reduces obesity. At the same time, healthcare costs are sometimes lower in highly developed cities, because people are able to purchase services in bulk.
Nevertheless life in big cities and their packed suburbs often increases levels of psychological stress, anxiety, confusion and fear. It is estimated that 25 percent of all Brits suffer from some kind of irrational fear. Some of these phobias are almost certainly boosted by the breakdown in social fabric that often accompanies rapid urban growth.
Alongside urbanisation, though, is the growing challenge of digitisation. As with the growth of the physical city, the spread of the 'digital city' presents wonderful benefits. (See the 2020Plus leadership editorial on innovation architecture, which features the story of Salvatore Iaconesi.)
The expanding digital city, however, opens up huge questions about social identity and cohesion. In an age where more and more people derive at least part of their identity from their experience in the cyberworld, how can we produce communities in which people also feel vitally linked to the human beings around them?
Recently, Google released a video which shows a man leading a tour of the Hadron Super Collider in Switzerland for the benefit of an American school class, via the internet. As he cycles and walks through the immense tunnels that make up the facility, the guide sends video to the class via the camera built into his shiny new Google Glass specs.
As he inspects the machinery around him, the guide also watches a live video feed of the classroom, which is showing in one corner of his vision.
Is this the way we will converse in the imminent future? And will people walk into things more often if they're reading text or watching video while they move about? (In some parts of the US, this is already such a problem that police have introduced fines for people caught texting while walking down the street.)
Under the influence of Google Glass - no doubt a wonderful innovation in other respects - will we learn to ignore someone standing beside us, while chatting with people we alone can see? We've quickly learned to do this with mobile phones, but how much worse will our social intercourse become when we can, while on the move, see as well as hear remote interlocutors?
Will tragedies like the ones in Ohio and Austria occur more often in the near future, partly because people are paying less attention to their immediate environments and the people in them?
Will Google Glass and all the other cool communications gadgets make us, in the end, socially blind?
There is no direct link between peoples' use of communications technology and the horrific situation of the three young women in Ohio. The blame rests squarely on the shoulders of the perpetrators.
Yet the story serves as a useful reminder of how important it is that we each live and pay attention within our physical space and not just the virtual one. Society only functions when we each stay fully aware of our real-time environment; when we each learn to say, 'I am society'.
It might already be time to ask ourselves: 'If my smartphone, tablet or laptop broke down tomorrow, would I still have any friends and would I still know what's going on in my world?'
Click here for Mal Fletcher's BBC Radio interview on this subject.