I don't guess I understand your requirement that "free speech" and "anonymity" be linked. There's always at least two sides to this argument:
1) People have a lot to say as long as their are no repercussions for them
2) The value of what someone says is diminished if they cower in anonymity to say it
These are obviously quite different and very polarized. You/me/anyone isn't going to change this - most people are going to identify strongly with one of these and that's that. It's a Liberal/Conservative, Right-to-life/Right-to-choose type of argument IMO - full of emotion, lots of heated debate, and neither side could ever convince the other to switch sides.
For the non-USA folks here, the 4th amendment: http://en.wikipedia.org/wiki/Fourth_Amendment_to_the_United_...
US supreme court finalizes gift of immunity to the telecom giants http://www.theguardian.com/commentisfree/2012/oct/10/supreme...
Tor operator charged for child porn transmitted over his servers http://arstechnica.com/tech-policy/2012/11/tor-operator-char...
There's a ton more information here: http://law2.umkc.edu/faculty/projects/ftrials/conlaw/rightof...