The six-month operation targeted internet users who access child abuse images but has already led to charges for serious sexual assault.
Among the several hundred people arrested across England, Wales, Scotland and Northern Ireland are workers who had access to children through their jobs and had no previous contact with police.
The massive investigation, involving 45 police forces, led to hundreds of children being "safeguarded", the NCA said.
It stressed that none of those arrested is a serving or former MP or member of the Government.
More top news
A Para who won the Victoria Cross gave up his military history studies just weeks into the course as he wanted to be a part of it instead.
Approaching Atlantic frontal systems will give a wet and windy night right across the UK.
Star Trek's Captain Kirk said he will not be able to say a final goodbye to Mr Spock because of a charity commitment in Florida.