I remember going to a talk given by the developer of something similar (can't remember the name of the site, sorry, but was given at a university, so probably a charity or public sector project of some sort) and apparently there are lots of issues with making data about this type of thing publicly available because there are malevolent parties who will try and take advantage of information about such situations in certain ways. Think they said a lot more - the talk was a while ago, but it was an angle that I hadn't thought about and I recall they had to have a screening process for whom they made information available to.

(Edit: this is the talk: http://stadium.open.ac.uk/stadia/preview.php?s=29&whichevent...)