Half the time, the media take their stories from rumours grown in someone's head, Chinese whispers, or even just plain fiction thought up by the article writer; it's certainly not unknown for a bystander to over-hear or be told directly, the story as to what happened and how it happened, and that it actually turns out to be true. Sometimes, the people on the ground know more than the police or the general media (take the Rhys Jones murderers for instance, people knew who they were, it had filtered through the local community before the plod had got to the lowlife ...-bags - and I'm not suggesting that names should have been posted in that instance as it could have led to unfounded revenge attacks etc, I'm merely using it as an example for the locals sometimes knowing more than the official channels).
Whilst there has to be a level of sensitivity applied, this has to be kept in context, and the internet (and wiki) are a place for open discussion, opinions and to a degree, a rumour-mill - without this, wiki would struggle to survive.