The part of the article that strcu a chord with me the most? In accordance with the fair use act, I cut and paste for you the polotics of fear:

So, in the phrase "50,000 paedophiles", the word 'paedophiles' is probably wrong. And, if you want evidence that this bears the hallmarks of a moral panic, you might examine the number as well. Fifty thousand paedophiles! None of the reports explained how it was reached, and so I called the NCA. What was the source? It came, I was told, from a 2013 threat assessment. The spokesman read me the relevant passage. "Although it is clearly not possible to establish a precise figure," he said, "CEOP estimates that there were around 50,000 individuals in the UK involved in downloading and sharing indecent images of children in 2012." Right, I said. And how is that figure reached? "It's on the basis of investigations and indications from partners and collaborations," he said vaguely. "Operational experience with partner investigative agencies."

OK. The funny thing, though, is that it's not the first time this number has come up. In 2008, a Swiss NGO said: "Recent figures suggest some 50,000 paedophiles are prowling the internet at any one time." In 2006, the US attorney general said the same thing. He attributed it to the TV show Dateline. Dateline attributed it to the FBI. The FBI, Dan Gardner learned for his book Risk: the Science and Politics of Fear, didn't know where the figure had come from. In fact, no one does.

Good find, BTW.