It was once an industry too taboo to talk about, but not anymore. It's the other Hollywood. It has changed technology and can be found in millions of homes, hotel rooms and hard drives across the country. But today, the producers of what's politely called "adult content" face the biggest challenges in their industry's history.

CNBC presents "Porn: Business of Pleasure," an original one-hour documentary reported by CNBC's Melissa Lee. CNBC, First in Business Worldwide, takes an unprecedented look inside the multi-billion dollar pornography business, from the threats to its profitability to exclusive behind-the-scenes interviews with the industry's biggest "stars " to the one issue-technology-that could bring down the adult industry.

The documentary looks at how porn is no longer a business in the shadows, and how its top performers are increasingly building crossover careers in mainstream media and even in businesses far removed from the adult film trade. Lee details how pornography is a product millions of global consumers want -- and want often. In fact, every second $3,075 dollars are spent on adult content, more than 28,000 Internet users are viewing it, 372 Internet users are typing adult terms into search engines to find it, and every 39 seconds a new pornographic video is produced in the United States.

Despite the output and the demand, porn is under attack -- and not just by activists who decry it as degrading to women, dangerous to children and socially corrosive. The assault comes principally from the Internet, where more and more adult content is free and where anyone with a video camera can be a producer and anyone with an exhibitionist streak a viral movie star. Industry sources say DVD sales are down 50-percent in the last year and that's due largely to free content and piracy. Ironically, the very technology that fueled porn's growth -- and created the privacy so many consumers craved -- now threatens to cripple the business.

This hour also looks at the unlikely next generation of executives: women. They're not just in front of the camera; they're behind-the-scenes at all levels-running studios, directing films and starting the new adult companies. Lee speaks with some of the key players to get their thoughts on how women are changing the business as well as the products of what used to be a business run by men, for men. Plus, CNBC goes home with Jesse Jane, one of the industry's best-known performers, and even reveals her true identity.

Other interviews include Steven Hirsch, CEO of Vivid Entertainment; adult film actress Sasha Grey; Joy King, vice president of special projects at Wicked Pictures; Samantha Lewis, CEO of Digital Playground; porn producer and star Max Hardcore and Pat Trueman, former director of Child Pornography and Obscenity at the Department of Justice.

Melissa Lee is host of CNBC's "Fast Money" (M-F, 5PM & 12AM ET) and host of CNBC's "Options Action" (Fridays, 11:30PM ET). Sanford Cannold is the executive producer of "Porn: Business of Pleasure." Justin Solomon is the producer, Samantha Wright is the coordinating producer, Steven Banton is the editor and Tyler Mathisen is CNBC'S managing editor. Ray Borelli is the Vice President of Strategic Research, Scheduling and Long Form Programming.