" 
 :::OK. I'd like to suggest that this article should take brief notice of un-designed consequences both good and bad, and that a sentence, two at most, on what those consequences are should then be supported by full references including quotations. Or in a footnote, but personally I think the present system works well. Tim makes a good point in that we should also take notice of the many anecdotes of ""a helmet saved my life"". Since the existence of many of these is not controversial, perhaps we should just have a sentence describing them. If we want a reference we could use http://cyclehelmets.org/1209.html, though Tim and Linda might reasonably have further suggestions.   "