Harmer is part of a cadre of anti-porn activists seeking new tactics to fight an unprecedented deluge of porn which they see as wrecking countless marriages and warping human sexuality. They are urging federal prosecutors to pursue more obscenity cases and raising funds for high-tech brain research that they hope will fuel lawsuits against porn magnates.

"It's the most profitable industry in the world," he said. "But I'm convinced we'll demonstrate in the not-too-distant future the actual physical harm that pornography causes and hold them financially accountable. That could be the straw that breaks their back."

The activists' adversary is a sprawling industry that, by some counts, offers more than 4 million porn sites on the Internet, that in the United States alone is estimated to be worth $12 billion a year. A tracking firm, comScore Media Metrix, says about 40 percent of Internet users in the United States visit adult sites each month.

Porn products are featured at popular sex expositions and retail chains such as Hustler Hollywood. Major hotels provide in-room porn, and adult film stars are now mainstream celebrities. Mary Carey attended a VIP Republican fundraiser in Washington in mid-March; Jenna Jameson's "How to Make Love Like a Porn Star" hit the best-seller lists and she hosted a racy pre-Super Bowl party in Detroit in February.

As much as there is national consensus on the evils of child pornography, there is none whatever on porn featuring adults and marketed to them. It's more pervasive than ever, yet activists and experts disagree bitterly over the extent of harm it causes.

"The form of entertainment is no problem," said Paul Cambria, general counsel for the porn industry's Adult Freedom Foundation. "There are individuals who are going to react abnormally to normal material, but it's not a problem for the average person."

For every couple driven apart by porn, there are others whose relationship is enlivened, Cambria argued. He dismissed contentions that porn is highly addictive or brain-damaging.

"The Internet is the perfect delivery system for anti-social behavior -- it's free, it's piped into your house," said Mary Anne Layden, a psychologist and addiction expert at the University of Pennsylvania. "Internet porn is probably the biggest miseducation system we can devise in terms of sexuality, misuse of women."

This is cache, read story here