(...) And those restrictions should apply to private individuals and businesses just as much as the police. Not more. Not less.
Thinking about this, I'm not sure. At what point do we have a right to search for and forcibly remove information about us that we suspect is held by a nosey neighbour? (Especially if they're not suspected of actually trespassing and planting bugs or anything, but only collecting publicly available information.) We have a right to decide what the Government should and shouldn't do because they're working on our behalf, and I'm okay with democratically agreed restrictions on commercial activity to an extent, but I'm less keen on restricting personal non-commercial activities in general.
Protecting privacy is undoubtedly a good cause, but even when pursuing a good cause, we need to be mindful that we don't end up using questionable means to do it. I think the DIA's attempt to address child pornography is instructive here, because child pornography is, IMHO, essentially an extreme kind of invasion of privacy. The DIA has ended up invading people's privacy (by snooping on Internet connections) in an attempt to address child pornography, so, IMHO they're essentially invading privacy in an attempt to protect privacy.
It may be worthwhile looking into anything that can be done to reduce the unnecessary disclosure of private information in the first place, because otherwise I think we may end up essentially trying to belatedly close the proverbial stable door. Simply outlawing an easy invasion of privacy may sound good in theory, but for this to work, either those who would invade our privacy must voluntarily decide to obey the law (and we already know this is not going to happen), or we must perpetually monitor and control their activities to ensure they do (which may require international government cooperation in monitoring and controlling people that itself invades people's privacy).
No doubt there are many cases where prevention isn't possible, but I think that because new privacy issues have only recently begun to come about with modern technology, there's a considerable amount that people could be doing to protect their privacy, but generally aren't, like all this kind of stuff: Encrypt all the things!
For a start, if we got Government-run organisations supporting security measures like DNSSEC and PGP/GPG signing/encrypting e-mail for communication with the public (anything else?), then perhaps we could help get past the chicken/egg problem with potentially beneficial privacy measures, and kick-start broader adoption (which would eventually help to protect citizens from their governments).