Tackling child pornography is often seen as 'organised crime' and this week David Cameron, the UK PM, announced some new steps and this led to a figure being given by a former CEOP head on BBC Radio 4:
There are 50,000 predators, we're told by CEOP, downloading images on peer-to-peer, not Google, peer-to-peer. Yet from CEOP intelligence, only 192 were arrested last year.
Link:http://www.pcpro.co.uk/news/383215/p...-ex-ceop-chief

Elsewhere an Opposition speaker claimed; citing the same figures with "spin" IMO:
Despite identifying 50,000 cases of British residents accessing images of child abuse online last year, Ceop had pursued only about 2,000.
Link:http://www.bbc.co.uk/news/uk-23393851

CEOP is the UK Child Exploitation and Online Protection Centre, originally a LE body, it now has extensive commercial and charity funding.