Attorney General Eric Holder and Homeland Security Secretary Janet Napolitano said Wednesday a 20-month law enforcement effort called Operation Delego targeted more than 600 Dreamboard members around the world for allegedly participating in the private, members-only Internet club created to promote pedophilia.

Numerous participants in the network sexually abused children ages 12 and under, produced images and video of the abuse and then shared it with other club members, according to court papers released in the case.

At a news conference at the Justice Department, the attorney general called the criminal activity a "nightmare" for the children and said that some of the children featured in the images and videos were just infants.

In many cases, the children being victimized were in obvious, and intentional, pain - even in distress and crying, just as the rules for one area of the bulletin board mandated, the attorney general said.

AP