The illegal sex trade is an abomination. It's also a reality.

In a groundbreaking report released on Wednesday, researchers at The Urban Institute's Justice Policy Center provide the most comprehensive look to date on the size and dynamics of the illegal sex trade in eight major American cities. Some of their conclusions are shocking.

What follows are five of the most interesting insights to be gleaned from the 339-page study.

1. How social media facilitates prostitution

Of all the things revealed in the report, this has got to be the most shocking -- and disturbing if you're a parent.

The role of social media came up time and again throughout the study. Most notably, it's used as a tool to recruit new prostitutes into the industry.

As the authors note (emphasis added):

Pimps will often [...] recruit from anywhere and everywhere, including train stations, bus stops, bus stations, clubs, homes, schools, detention facilities, group homes, and homeless shelters. They will also use Facebook and Myspace to recruit new women and girls.

2. Atlanta has the largest commercial sex industry

Of the seven cities examined (there were actually eight, but the results from Kansas City weren't meaningful enough for the authors to include), Atlanta was found to have the largest commercial sex trade, estimated at $290 million in 2007.

3. Atlanta also has the most pimps

The definition of a pimp isn't as settled as one might think. Formally, it's an individual who "controls the actions, and lives off the proceeds, of one or more women who work the streets."

But as the study goes on to note, "Debate exists over who is and is not considered to be a pimp, particularly because legal definitions between municipalities and countries can differ from popular and public understanding."

For instance, a 25-year-old respondent who fit the vocational profile explained:

I'm not a pimp. ... A pimp has the hat, the cane. Those are pimps. They have guidelines, just like gangs. What's happening now, it's nothing like what it is supposed to be like. It is just money for habits ... I don't know if you heard of renegades. I think most are renegades now. Even if girls have pimps, they're boyfriend and girlfriend. A pimp keeps all the money and dishes it out. That hardly happens anymore.

Whatever a pimp is or is not, however, the report concluded that Atlanta has the most of them.

4. Structure of the industry

Every industry has a structure. The illegal sex trade is no exception. Additionally, the structure is in constant flux, morphing in response to technology, law enforcement, and other market realities.

In the past, the industry mainly consisted of street prostitution. Today, however, it's become more segmented.

According to the study, a majority of business takes place on the Internet. Street prostitution is the next most prevalent. The industry is then rounded out by illicit massage parlors, brothels, and escort services.

5. The role of the Internet

As already noted, the Internet has fundamentally transformed the illegal sex trade.

It's shifted the venue from the street corner to Internet chat rooms and online classified ads. It's facilitated price discovery and marketing. And it's made recruiting easier and law enforcement harder.

In Denver, for instance, law enforcement officials have seen a decrease in the street market for prostitution, but an increase in the number of advertisements for escort services online.

And in Dallas, "Advertising via the Internet is said to increase during winter months and in periods following increased law enforcement investigations of street-based sex work and sex trafficking."

Foolish bottom line

To be clear, these observations are just the tip of the iceberg. The full report covers much more and the insights derived could easily serve as a catalyst for positive change. Here's hoping that they do.