We were pretty skeptical last year, when podcast pioneer Adam Curry predicted a podcast porn explosion, and even more so when the mainstream media went iPod porn crazy.

Now a statistical analysis of the content on the Web has found that there is actually a lot less adult content on the Web than some may have thought.

The analysis, by Philip B. Stark, a professor of statistics at the University of California-Berkeley, consisted of an examination of Internet search queries and a random sample of Web pages taken from Google and Microsoft’s Internet indexes. It found that just 1 percent of all Web pages contain sexually explicit material.

The Stark naked analysis was presented in a federal court hearing last week in Philadelphia, in a suit brought by the American Civil Liberties Union (ACLU) against U.S. Attorney General Alberto Gonzales and was obtained Monday by the Mercury News.

“One of the things we think came out of the government’s study is that the chance of running into graphic content on the Web when filters are on is extremely low,” said Catherine Crump, staff attorney at the American Civil Liberties Union.

The ACLU said the analysis did not appear to substantially help the Justice Department’s efforts to prove that criminal penalties are necessary to protect minors from exposure to sexually explicit information on the Internet.

The Justice Department had commissioned the study as part of an effort to resurrect the Children’s Online Protection Act, which was signed by President Clinton in 1998, but was immediately challenged by the ACLU.

Stark’s study found that only 6 percent of all queries returned a sexually explicit Web site, despite the consistent popularity of queries related to sex. It also found that the filters that did the best job blocking sexually explicit content also inadvertently blocked lots of content that was not explicit.

Government witnesses argued that, while the percent of sexually explicit Web pages was small, it still amounted to a huge number. “A lot of sexually explicit material is not blocked by filters,” Stark wrote in the conclusion to his study.

Links to Professor Stark’s analysis, and reports by rebuttal witnesses, are available as .pdf files via the Mercury News article.