Free speech vs Anonymous

There's an interesting article on Wired here about how two female law students at Yale sued the owner of a website to reveal the identities of anonymous posters that had threatened to assault and rape them.

It has raised an interesting debate as to whether anonymity on the internet is a "right" as much as free speech is a "right" (at least in the US). For example, I would very much like to allow anonymous comments on this blog, but I have not been able to see how to do it, and I don't know if it's possible. However if someone did post something offensive or threatening, is there a legal recourse for someone to resolve this? I myself am anonymous. Who would they sue? The owners of blogspot (ie Google)?

Looking at the website in question, toting itself as "The Most Prestigious College Admissions Discussion Board in the World", the design is amateurish, plain, and amongst the postings titled "What are my chances at the Ivy leagues or Stanford" or "Most Conservative College/University", there are multiple postings with no content with just a derogatory words repeated "GOOK GOOK GOOK", "N...ER N...ER N...ER" and so on.

The owner of this website used the arguments of "free speech" to resist handing over information that might identify the posters that threatened the women. I think the argument of free speech ends when feasible threats of personal injury and assault start (in all cases). Given the nature of the website (or the 'style' if you will), I think the administrator is a lazy bastard who can't be bothered moderating the comments, and then gets his back up when compelled to do something that "may" sully his reputation, however I use the scare quote around "may" because if you check out the website, it would be hard going to find anything that could be construed as contributing anything good to his reputation.

The pace of technological advances have far outstripped the capacity for laws, politics and cultural norms to keep up. And the resolution of this case may have far reaching consequences.