> When discussing privacy, I find it useful to distinguish three types: a) privacy from government, which is fondamentally not a technical problem but a political one

I think that this is not quite true. At its best, privacy from the government is granted willingly by the government; this is a political process. However, one might be dealing with a government that explicitly revokes certain privacies, or one might not trust a government's guarantee to respect certain privacies, in which case the political problem is once again technological. (Or of course one could trust one's government implicitly but not the next government, or one could trust one's government to try to do things well but fear government stores of data as a juicy target for hackers.)