Re: for some definition of paedophile...
"I know that the amount of evidence required by the CPS to even bring the cases to court is massively more than people seem to think. "
Being a cynic I would say that the amount of real evidence obtained is often irrelevant. Once the Police have decided that there is the prospect of a career enhancing case - then they keep going. A blind alley is often attributed to "clever criminals" or "lying witnesses". They can even resort to off the record threats to try to make alleged victims falsely incriminate the alleged perpetrators.
Naturist families are easy targets. All the Police need is an "anonymous" phone call to trigger an investigation. They know they will find something in the family albums that they can use as a hook for a bigger investigation.
In one case the Crown Court judge said that if the police hadn't culled a few seconds from a naturist family's home video then he wouldn't have noticed the alleged indecent shot. That was the only prosecution evidence. The defendant pleaded guilty to a "technical offence" to avoid a possible jail sentence. The judge apologised for the severity of the mandatory minimum sentence. He then spent most of his probation playing games of chess with his probation officer who recognised the injustice.
A naturist family had their children taken away - and took several years to get their conviction quashed. Their offence was having kept some family holiday pictures discarded in the "reject" box.
A jury threw a case out. Under cross examination the prosecution's star expert witness agreed there was nothing actually indecent about a set of naturist holiday pictures that was the prosecution's only evidence. The judge had repeatedly ruled that the prosecution's expert witness was making personal comments that were outside her professional remit.
People have been prosecuted for possessing a book that could simultaneously be bought at W H Smith.
When the police get desperate about how such an investigation is proving fruitless - they can be tempted to mount dawn raids on anyone in an accused's address book. Especially if that address is of a school teacher, scout master, or IT techie. They hope the fishing expedition will turn up something on a PC or phone. By making an arrest on "suspicion of conspiracy to..." they side-step trying to obtain a search warrant from a magistrate with no evidence. They then claim immunity from complaints by having followed "due process".
These things have happened - and should not have done. Institutions have become numbers games - with the general law-abiding public as their cannon fodder.