Sadly the rate of recidevism (return to illegal activities) for pedophiles is extremely high. It truly is something like a disorder that can't be reformed out of you. For their own good and for the good of society they simply should be confined to an adults only facility after their prison term is finished and allowed to lead as normal life as possible within the confines of the institution (rather like a quarantine of some kind). It's the only way to truly protect children.

And I feel that I must make a personal disclaimer here, for fear that someone would brand me as too cruel. My opinions are definitely affected by having been abused by a non-related adult when I was a child. Normally I have pity and can see the good in anyone, but I find it very difficult to be dispassionate about somone charged or convicted of a sex-crime involving a child or child-pornography.