It is likely someone in your household is using the file sharing software called Kazaa to share and obtain music files from other users. This leaves an opening to the internet that can by compromised. The FBI is very familiar with these tactics.
I did a search for ‘child porn reporting’. This site lists these contact points.
http://vachss.com/help_text/report_child_porn.html
Child Exploitation and Obscenity Section
Criminal Division
U.S. Department of Justice
1331 F Street NW, 6th Floor
Washington DC 20004
Phone: 202-514-5780
www.usdoj.gov/criminal/ceos/
The Child Exploitation and Obscenity Section (CEOS) of the Criminal Division, U.S. Department of Justice, has supervisory responsibility for Federal statutes covering obscenity, child exploitation, child sexual abuse, activities under the Mann Act, sex tourism, missing and abducted children, and child support recovery.
Innocent Images National Initiative
Federal Bureau of Investigation
www.fbi.gov/hq/cid/cac/innocent.htm
The Innocent Images National Initiative (IINI), a component of the FBI’s Cyber Crimes Program, is an intelligence-driven, proactive, multi-agency investigative initiative to combat the proliferation of child pornography/child sexual exploitation facilitated by an online computer.
ICE Cyber Crimes Center
U.S. Immigration and Customs Enforcement
Toll-free: 1-866-DHS-2ICE
/www.ice.gov/graphics/investigations/services/cyberbranch.htm
U.S. Postal Inspection Service
Inspection Service Operations Support Group
222 S. Riverside Plaza, Suite 1250
Chicago, IL 60606-6100
www.usps.com/postalinspectors/kid-porn.htm