In my idealized future world I envision 2 things happening for pedos:
1) We (meaning scientists

) figure out a sure fire way to alter their brains so that they're no longer attracted to kids.
2) We (again, scientists/engineers

) develop virtual reality pods (ŕ la The Matrix) that the pedos are required to live in for the rest of their days. They'll be able to live out their sexual desires in those pods and no real children shall ever be harmed.
And please don't take me seriously on these two ideas because I'm pretty sure I was drinking when I thought them up.