The Child Exploitation and Online Protection Centre (Ceop) has said it in concerned by the rise in the use of the 'hidden internet' - heavily encrypted forums and pages that allow abusers to cover their tracks.
UK daily users connecting to secret or encrypted networks increased by two thirds in 2012, Ceop reported, although not all of these will use the hidden internet for criminal means.
This number is set to reach to 20,000 by the end of this year.
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