I've just been discussing this with DH - and I said 'so, how was the PIE thing in 70s stopped?' and he said 'well, a load of them were arrested, weren't they?' And indeed they were - Peter Righton, for example.
DH has (v carefully) googled it - this article was published in 2014:
www.independent.co.uk/news/uk/politics/looking-back-to-the-great-british-paedophile-infiltration-campaign-of-the-1970s-9155610.html
Exactly the same tactics going on here. PIE never really went away. Getting the "P" added onto the LGBTQ alphabet soup... exactly the thing the PIE were trying to do in the 70s - attach itself to a libertarian/minority rights movement. They centred the campaign on "child's rights" - as opposed to campaigning for adults to have sex with children - which is far more likely to have the public up in arms.
But it is always about normalising children having sexual relationships, and abolishing the age of consent - and claiming that paedophilia in itself is not harmful. "NOMAPs" is just the latest incarnation.
Note that O'Carroll was brought down by a News of the World exposé - I was among those cheering at the demise of the NOTW - but you know, that sort of investigative journalism is still very much needed.