New York law officials this week announced agreements with Verizon, Time Warner Cable and Sprint that would empower the ISPs to block access to child pornography from significant sources including newsgroups and purge ISP servers of porn Web sites.

Under the terms of the agreement headed up by New York Attorney General Andrew Cuomo, the ISPs will eliminate access to child porn newsgroups and purge their own servers of child porn Web sites identified by the National Center for Missing & Exploited Children (NCMEC). The deal follows an undercover investigation conducted by New York lawmakers, which reviews millions of pictures over several months to detect the significant sources of online child porn.

"The pervasiveness of child pornography on the Internet is horrific and needs to be stopped," Cuomo said in a statement. "We are attacking this problem by working with ISPs to ensure they do not play host to this immoral business."

The agreement with the ISPs comes after an investigation by the New York Attorney General's office, which found newsgroups were a major source of online child pornography. These sources serve as a bulletin board of sorts where users can upload and download files, according to New York officials. Verizon, Sprint and Time Warner Cable will now block access to all child porn newsgroups. The investigation uncovered 88 newsgroups that contained a total of 11,390 "sexually lewd photos featuring prepubescent children, and in some cases, photos of children being raped and sexual activity involving animals," the New York Attorney General's office reports.

The investigators developed a system to identify online content that contained child pornography, which depended on the "hash value" of online photos. Once the hash value is identified and collected, it can be used to digitally match the same image wherever it is distributed. The Attorney General's office built a library of hash values related to images of child pornography and then investigators were able to filter through thousands of files to identify illegal images.

By cutting off access to the source, lawmakers can help lessen the amount of child pornography online.

"This is a major step forward in the fight against child pornography. Attorney General Cuomo has developed a new and effective system that cuts child porn off at the source and stops it from spreading across the Internet," said NCMEC CEO Ernie Allen in a statement.