The way I see it someone created the account as a joke, it spiraled out of control, and so rather than get exposed and take the resulting flak, they decided to try and take the moral high ground and present it as if they were trying to highlight a serious issue. Completely pointless – making it illegal for paedophiles to access the internet will make no difference whatsoever – it’s not as if they were scared of breaking the law prior to their conviction(s).
And yep as pointed out above, the same people who act outraged over Mr Glitter will quite happily watch a Polanski film, listen to The Who & R Kelly.