I�m not sure that your comparison, Gromit is entirely valid.
The hunting down of alleged paedophiles in the UK is, although completely abhorrent, comparatively rare. The modern phenomenon of people suspecting others of child abuse never ceases to amaze me. It is often demonstrated by people who exercise more neglect or abuse upon their children than is good for them, but nonetheless they feel outraged when any suspected �nonces� come to their attention. Nonetheless, their motives are almost understandable (though not condonable) when they see those who are convicted of child abuse let off with such derisory sentences. I would not describe their actions as a witch hunt, although it can certainly be barbaric.
The situation in Africa described by Geezer is somewhat different. Child abuse is provable and does go on. Witchcraft is not. Also, the manner of the executions of the "witches" was most certainly extremely barbaric and is deliberately designed to be so. The murders of the paedophiles you cite were not so exhibitionist and in one of the cases seemed accidental (the assailant it seems merely wanted to give his victim a good hiding).
It does not do to compare fairly isolated incidents in the UK with what seems to be widespread practice in Africa. There are people in the UK who are far less civilised than many in Africa and a generalisation to tar all of them in either place with the same brush is not appropriate. However, there is no doubt that some parts of Africa are still very much steeped in religion and suspicion of things such as witchcraft and I think they need to catch up a little. Whether they ever will is debateable.