Cable companies that offer Internet service to 112 million homes said last week that they will act to reduce child pornography on home computers.

The companies have entered an agreement with the National Center for Missing and Exploited Children. If the center finds a child porn Web site hosted by a server managed by one of the companies, "the company will shut that site down," said Rob Stoddard of the National Cable and Telecommunications Association.

If a cable company finds a child pornography site on a server it is managing, it will shut the site down and report it to the center, Cox News Service reports.

This is encouraging. The companies offer services to 87 percent of the nation's residences.

"We are deeply grateful for this industry-wide attack on child pornography," said Ernie Allen, president and CEO of the National Center for Missing and Exploited Children. "It is not possible to arrest and prosecute every offender. We must be creative and build new public-private partnerships to address this insidious problem more effectively."

The agreement "will limit the ability of predators to store and exchange images of exploitation of those who are, by definition, among the more vulnerable in society," said Patrick C. Lynch, the attorney general of Rhode Island and president of the National Association of Attorneys General.

This is the sort of initiative that is needed to root out and eliminate child pornography from the Internet. The companies should be commended for acting responsibly.