Imagine that all the private things you would never do in front of someone else were being watched and leered over by a third party. Imagine it had been happening for months, even years. Now try to imagine that not only had all those private moments been seen by someone else but they had videoed every last moment for posterity.

If that was happening to you (and how do you actually know it isn't?), you would join an ever-growing number of people who have been victims of voyeurs in the last 10 years.

According to a study in 1995, one in five women has already been the unknowing victim of a voyeur, and that could be just the tip of the iceberg. It is hard to tell. If you have been watched by a half-decent Peeping Tom you will have no idea it happened. And one of the consistent traits of voyeurs the world over is that they exhibit a high frequency of offences per individual. Recent studies of 62 voyeurs showed they committed 52, 669 crimes against 55,887 victims. That's an average of 850 crimes per person.

Whatever the chances of falling victim to a voyeur are, they are increasing every time a camera phone or a digital camera is sold.

Terry, a founder of Projectvoyeur.com, estimates that when the site began most of the pictures received were simply scanned photographs. Now, 99.9 per cent of them are from digital cameras or phones.

Jack Whitfield, who started Privatevoyeur.com, agrees, "Digital cameras and phone cameras make it easier for the voyeur to take photos and put them online, where they can be immediately accessed by the world." Global sales of camera phones this year will top 150million.

Voyeurism may be as old as sex itself but in the last decade "the great unpoliceable" (as the internet was referred to on one voyeur messageboard) and gadgetry have transformed it from something people had to be spoon-fed in the form of peepshows, into something that anyone with the inclination and a meagre budget can pursue for themselves. Now voyeurism is one of the most prevalent sexual disorders in society.