25 July 2011 Last updated at 00:04 ET
Studying the web's impact on sex offenders
Mark Ward
Technology correspondent, BBC News
Operation Alpine recovered a server holding a huge store of images of abuse
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In May 2011, Lincolnshire Police announced that it had broken up a web-based news group that sold and distributed images of child sex abuse.
link-
http://www.bbc.co.uk/news/technology-14234281