In an Information Security article a few months back, Bruce Schneier (author of Schneier on Security) and Marcus Ranum put some points forward for and against internet anonymity. I have to admit that I agree with Schneier and find Ranum's argument quite weak. He appears to suggest that the main reason to enforce identity is to avoid spam. The tools aren't great, but there are already mechanisms in place to address this. Criminals are always getting better at finding ways to exploit weaknesses in internet technologies increasingly at the heart of the way we shop, interact, work, entertain and inform ourselves. We just have to keep up with the pace in the cat and mouse game. Sacrificing anonymity, and the right to privacy, is too great a cost for just avoiding emails about Viagra (tm) and Nigerian generals with a stash of cash to move out of the country.
What is the great danger of not being anonymous? Well it's all the inferring that goes on about facts that get gathered around the things you search for, shop for, chat about, view and listen to. These are then used to categorise you for advertising, inclusion or exclusion from groups or activities. NetFlix provided a great example of this last year. Just weeks after the contest began, two University of Texas researchers showed that with the NetFlix data one could identify users and in some cases their political leanings and sexual orientation.
Getting back to Schneier's point, trying to implement a robust identification system, which criminals can not outwit or take advantage of, is not possible...
Mandating universal identity and attribution is the wrong goal. Accept that there will always be anonymous speech on the Internet. Accept that you'll never truly know where a packet came from. Work on the problems you can solve: software that's secure in the face of whatever packet it receives, identification systems that are secure enough in the face of the risks. We can do far better at these things than we're doing, and they'll do more to improve security than trying to fix insoluble problems.