http://www.bbc.co.uk/news/uk-24144417

Presumably he'd have to give them notice of pre-paid credit cards too.

If you can't do the time, don't do the crime.
In this case the times includes being checed up on for life.
He should have though of that before he committed such a vile offence in the first place.

Well these changes were brought in after his release. Considering many buy images over the internet it will allow the police to trace if he did that and find out the sites that he used to catch others. Also no criminal really thinks about the sentences, they imagine that they would get away with it. How would anyone know that X was downloading child porn etc? It is not the sentencing that deters criminals, it is the certainty of getting caught that deters them.