Klipspringer:
Surely if that can happen, it will happen already based on data which is already publicly available from other places. Ie, facebook, twitter, blogs etc ... All the identity information for those sort of sites can already be requested by government. Some of it is already out there and there is no need to request anything. We have seen many cases already of the likes of google and facebook being forced to hand identity information over.
Which is why I deleted my Facebook account ages ago. I have the choice to hand over my life to Facebook -- and I choose not to -- but I don't have the choice if the government passes a law allowing them to steal it without telling me.