The difference between crime and anonymity on the internet is that we can have a substantial influence on crime. If someone wants to commit a crime, he will likely be caught. If someone wants to be anonymous on the internet for a while, however, there is nothing anyone can do. "Never worry about what you can't control."[1] By that principle, security problems caused by the internet have to be solved by other means (or not at all, if the costs are too high).
About his suggestion to implement identification mechanisms in the network itself, I strongly disagree. Currently, the internet is a "dumb" network on which "intelligent" machines plug in and exchange information. If we add some intelligence to the network, it will be disastrous for civil liberties (selective filtering, browsing logs… all in very few places). Plus, such centralization will require the collaboration of most countries. If one ever get rogue, the "intelligent" network is doomed.
Also, the idea that most people taking advantage of anonymity are spammers or criminals is absurd. The default pseudo-anonymity of most discussions makes it possible to say things that you don't want your boss or customers to find in Google. Yes, we should live in a world of perfect tolerance where you could express a reasonable opinion on controversial issues without suffering ill effects, but we don't.
