More than 70 people have been charged in connection with the private site, which was called "Dreamboard" and gave members varying access to the material.

"To put it simply, we have charged that these individuals shared a dream - to create the preeminent online community for the promotion of child sexual exploitation," Attorney General Eric Holder told reporters. "But for the children they victimized, this was nothing short of a nightmare."

U.S. officials called it the largest prosecution of people who participated in an online child exploitation enterprise operated for the purpose of promoting child sexual abuse, disseminating child pornography and evading law enforcement.

The bulletin board, created in 2008, folded in the spring of this year when members became aware of the U.S. government's investigation, Justice Department officials said.

The 600 members of Dreamboard offered to trade images and videos of infants and children 12 and younger, contained in some 27,000 posts, the authorities said.

"The nature of this crime is abhorrent. These are some of the most disturbing images I think you will ever see," Holder said, adding that some victims were in obvious pain and crying.

Homeland Security Secretary Janet Napolitano said digital media recovered from those arrested in the United States included more than 1 million images of child pornography.

Of those charged in the United States, 43 have been arrested in this country and nine foreign nationals have been arrested overseas, including accused bulletin board administrators located in Canada and France, the officials said.

The board's three other administrators have yet to be identified and authorities were seeking to identify other members and the victims, they said. About one-third of the members were in the United States and the rest were overseas.

Arrests also took place in Denmark, Ecuador, Germany, Hungary, Kenya, the Philippines, Qatar and Serbia, among other countries.

(Reuters)

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