A very interesting article from Bruce Schneier:
Data is the pollution problem of the information age. All computer processes produce it. It stays around. How we deal with it — how we reuse and recycle it, who has access to it, how we dispose of it, and what laws regulate it — is central to how the information age functions. And I believe that just as we look back at the early decades of the industrial age and wonder how society could ignore pollution in their rush to build an industrial world, our grandchildren will look back at us during these early decades of the information age and judge us on how we dealt with the rebalancing of power resulting from all this new data.
Source: Schneier on Security