From: "Justin M. Streiner" <streiner@cluebyfour.org>
Aside from all of the business and legal sticking points that others
have
mentioned, there are also the technical aspects of capturing, storing,
transporting, analyzing, and managing those packets, and the appliances
that do the heavy lifting. As your traffic grows, that problem scales 1:1
linearly, at best, and more likely n:1 linearly, or worse. The added
overhead of the infrastructure needed to support this will also make
it more difficult to be price-competitive with your peers.
TL:DR; The reasons for doing this on any kind of general basis have to
be *EXCEPTIONALLY* compelling to make a business case for it, apart from
any possible legal ramifications.
I used asterisks *and* capital letters; that's about an order of
magnitude.
Don't forget staffing.
I am a little surprised no one has referenced Wired's recent article about
Libya's Internet Surveillance systems:
It's good reading and I think does a good job of summarizing both the
technical challenges but also the political implications of such a system.
-Keith