Child-porn study: US biggest source

More than 50% of the child porn images reported to the UK's Internet Watch Foundation can be traced to the US, the BBC reports. The rest of the "Top 7" countries were Russia, Japan, Spain, Thailand, South Korea, and the UK. IWF investigations "found nearly 2,500 US sites containing illegal images. The IWF study also said that some sites that contain the illegal content remain accessible for up to five years despite being reported to relevant authorities." Top US Internet service providers are working with the National Center for Missing & Exploited Children combating this problem (see "ISPs join child-porn fight"). Meanwhile, a change in British law will allow financial credit card companies there to cancel the accounts associated with cards used to buy child porn, CNET reports.