Arthur is an alleged john, a man who patronizes prostitutes. After his arrest on September 5, , a photograph of this year-old appeared on the Web site of the Chicago Police Department. Arthur not his real name was far from the only person so branded on this Internet portal. In the U. Experts believe that about 10 percent of these arrests are of the sex patrons, almost all of whom are men.

This may seem like a silly question with a one-word answer, but advocates battling sex trafficking say the reasons are actually quite complex and could be key to understanding the changing face of prostitution in modern times. Psychologists from international advocacy groups sat down with Johns in several countries to learn why they decided to pay for sex. The study has illuminated some personal stories of loneliness, to pure desire. Gone are the heydays of the local brothel or even the red light district. With the rise of the Internet, a new anonymity was born and with it a covert business model that blended in with local homes and businesses. Some Internet advertisements are from individual prostitutes and some are from pimps who run sex trafficking rings that exploit women captured into sex slavery through force, threats of violence or coercion. Experts say sometimes Johns may not even know the difference -- so a coalition of non-profits dedicated to abolishing modern day sex trafficking decided it was time to shift from interviewing women about why they were selling sex to asking why men decided to pay for sex.

An apparently average, thirtysomething, middle-class man, Ben had taken an extended lunchbreak from his job in advertising to talk about his experiences of buying sex. Shy and slightly nervous, he told me, "I am hoping that talking about it might help me work out why I do it. I, too, was hoping to understand his motives better. Ben was one of men interviewed for a major international research project seeking to uncover the reality about men who buy sex.

There's a stereotypical image of the kind of men who go to prostitutes. But how do they explain paying for sex? Fred and Laura go on walks, take weekend breaks away, amble round markets and often have meals out. They have a laugh together over things they've seen on TV. But they can fight and argue too.