On a cold morning in January, FBI agents converged on a modern brick office building in Koreatown in a mission conjured up at the highest levels of Washington: to rid the world of adult films by an obscure niche producer named Ira Isaacs.
From his 12th-floor suite above Wilshire Boulevard, Isaacs, a stout, fast-talking 56-year-old Bronx native with a short ponytail and a lopsided "soul patch" of black hair under his lip, sent out some stomach-churning porn.
Agents seized Isaacs' files and scanned his computer hard drives, and in July he was indicted on federal obscenity charges.
He pleaded not guilty to six felony counts of transporting obscene material and two counts of not properly documenting the ages of performers, although there is no allegation that they were underage.
Isaacs was barely known in the $4-billion adult entertainment industry in Los Angeles; his films, featuring bestiality and defecation, catered to a tiny audience.
Yet his was the first obscenity case brought in Southern California by a Justice Department task force formed in 2005 after influential Christian conservative groups demanded a crackdown on smut.
The task force's focus on bit players such as Isaacs demonstrates the difficulty of prosecuting pornography in an era when it is more pervasive than ever, with hard-core films offered by major hotel chains and cable companies, and X-rated content of every type exploding on the Internet.
Specifically, it raises a question of whether increasing public acceptance has shifted the legal standard of obscenity -- once aimed at the works of such authors as James Joyce, Henry Miller and William S. Burroughs -- so that only the most extreme margins of porn can be stopped.
The conservative groups who pushed for the initiative say no, and complain that it is virtually pointless to go after fringe figures whose material does not have the societal impact of big commercial productions.
Many federal prosecutors, meanwhile, feel obscenity cases are not worth the time and resources they take away from their main missions, such as stemming terrorism and organized crime.
By focusing on the most distasteful, extreme material, prosecutors are "picking off the low-hanging fruit," said Loyola Law School professor and former federal prosecutor Laurie Levenson. "What does this accomplish? That is the question. These cases take a lot of prosecutorial resources."
Department of Justice spokesman Bryan Sierra defended the Obscenity Prosecution Task Force's record, saying it has reversed years of neglect by the Clinton administration. "There was a lack of enforcement for nearly a decade," Sierra said. "One of the things we saw in that period was a proliferation of obscene material."
Still, the department has brought fewer than two dozen adult obscenity cases since the task force began. All are at the edge of the erotica spectrum, often depicting violence or defecation.
In an interview last month, Isaacs said the only people who received his videos were adults who ordered them.
He pointed out that late Italian artist Piero Manzoni defecated in tins; one of the tins sold for $70,000.
"It's shock art," he said. "Art could be how the audience reacts to it, not the piece of art itself."
Isaacs was producing glossy mailers for dry cleaners and pizza delivery joints when he first ventured into selling porn. He mostly distributes videos from other countries, but also has produced his own.
"This is the only crime you don't know you did until the jury tells you you did it," he said. "It's not like I'm selling illegal products. It's perfectly legal to own this stuff, share it."
Obscenity cases are inherently tricky. The U.S. Supreme Court created the three-part Miller Test in 1973 to define the crime: It must appeal to prurient interests, be patently offensive by community standards and have no literary, scientific, political or artistic value.
Jurors have a hard time deciding what their community's standards are and what constitutes art. For instance, do the plot lines and acting performances in the average X-rated movie give it artistic value?
Prosecutors have the option of bringing charges where materials are produced or where they are distributed, and frequently have picked Christian conservative areas to file.
Trying Isaacs on his home turf is a risk. Yet a win for prosecutors in Los Angeles would send a message that there are limits, even in the capital of porn.
The adult entertainment industry is watching closely. The Free Speech Coalition, an industry trade group, says the government should get out of the business of trying to dictate what adults can watch, with the exception of child porn.
"Should this small portion of so-called moral extremists define what the rest of the world chooses to see or not see?" asked Diane Duke, executive director of the group.
Mark Kearnes, a senior editor of Adult Video News, noted an irony: "The only people forced to look at this stuff are the jurors in the obscenity case."