In 1980, Congress passed the Parental Kidnapping Prevention Act, all 50 States passed the Uniform Child Custody Jurisdiction Act, and virtually every jurisdiction made interstate parental abduction a crime. In 1982, Congress enacted the Missing Children Act, requiring the FBI to record missing children in the National Crime Information Center (NCIC) computer to aid law enforcement agencies. The exact number of 'missing children' is not known, and a large percentage is recorded by police as probable runaways. The 1984 Federal Missing Children's Assistance Act (MCAA) called for a study to determine the actual number of children reported missing because the exact number is not known. Finally, the National Center for Missing and Exploited Children functions as the national resource center and clearinghouse and provides technical assistance to law enforcement agencies. Media attention, as well as photos of missing children on milk cartons and other containers, have helped to recover missing children.