A pan-European drive to use the financial system to fight online child abuse has succeeded in reducing sales of child abuse material using conventional payment systems – but research suggests that abusers have been driven underground, turning to anonymiser technologies to evade law enforcement, and bitcoin to pay for material.Experts from the European Financial Coalition Against Commercial Sexual Exploitation Online (EFC) report that images and videos of child abuse have become a currency in their own right, with abusers expected to provide new material in exchange for access.
http://www.theguardian.com/technology/2015/jun/05/online-child-abuse-driven-underground