I totally agree with hoobley. All the little pieces of information add up to help create a profile of the perpetrator. Sometimes just a little bit of information reported to Docs or the police is all they need to put evidence together and do something.
The legal system is far from perfect but if we lose faith in it then society crumbles and it is also not fair to the children involved.
I once got told about a serious crime and told the police straight away and they said that a few people had come forth but it felt so much better to tell them and feel like I was helping rather then keep the info to myself and carry that burden. I definatly think that abuse should be reported, I work with children and have witnessed what abuse can do to a smalll child and all children deserve to live in a safe place away from harm.