Stop Child Pornographers and Predators Act - Amends the federal criminal code to: (1) prohibit the production, distribution, receipt, or possession of visual depictions of prepubescent children (age 12 or younger) engaging in sexually explicit conduct; (2) prohibit the use of pornographic materials to facilitate sex offenses against minors; (3) ban the distribution in the United States of child pornography produced outside the United States; and (4) increase criminal penalties for sex offenders who have a prior sex conviction involving a minor.