In reply to Kevster:
These days kids don't have sleepovers at adults houses like that. No adult is generally left alone with a child for any length of time, or be behind closed doors with a child. Giving a child a lift home isn't something that is done without a witness. People keep a closer eye on coaching relationships. Any sports clubs with junior members will have a safeguarding officer who will have done basic training.
No system is perfect, but there have been massive changes in attitude and practices since the 1980s.
DBS checks have their place, but only show those who have been caught. Plenty of abusers haven't been caught. Others, like the Soham murderer manage to change name and get through, although changes were made to make it harder.
Children these days are taught at school age appropriate ways to look after themselves, and ways to deal with difficult situations. Even a pre school child can understand the pants rule.
http://www.ukclimbing.com/forums/t.php?t=653963&new=8442884#x8442884Post edited at 22:55