PHILADELPHIA (CNN) -- A businessman who sells access codes to enter pornographic Web sites said Friday that companies are becoming more aware of their responsibility to keep adult material away from children.

Laith Alsarraf, who runs AdultCheck, an age verification service that requires adults to input credit card numbers and other identification for free access to pornographic sites opened the government's defense of a law aimed at protecting children from sexual material on the Internet.

He said 3 million people pay $16.95 a year for the service, with about half the money going to Web site owners.

As for worries that customers' personal data could be exposed in cyberspace, Alsarraf said: "That information is never released, given out, sold, or disclosed."

The American Civil Liberties Union is challenging the Child Online Protection Act, which was signed by President Clinton in October but put on hold by a judge.

The law would require commercial Web sites to collect a credit card number or some other access code as proof of age before allowing Internet users to view material deemed "harmful to minors."

Violators would face up to six months in jail and a $50,000 fine. Supporters say the law is a sensible way to keep Internet pornography away from children. The ACLU contends the law violates the First Amendment, which protects free speech.

Alsarraf said most of the 46,000 sites offering links to AdultCheck offer pornography, with names like "True Confessions of Housewives" and "West Coast Teens." Such businesses are becoming more aware "they need to be responsible" in keeping the material from children," he said.

ACLU attorney Ann Beeson suggested Alsarraf had another motivation. "Wouldn't you agree you stand to make a large amount of money if this law goes into effect?" she asked.

"I'm hoping for a lot of things," he said. "That could be one of them."

The Associated Press contributed to this report.