I haven't been able to find a case cite, but this NYTimes story lays out the details. It is good to see that a court has recognized that blogs are important tools that allow us to express our First Amendment rights. Read on to get a quick summary:
The Delaware Supreme Court ruled Wednesday that if an elected official claims he has been defamed by an anonymous blogger, he cannot use a lawsuit to unmask the writer unless he has substantial evidence to prove his claim.
That standard, the court said, "will more appropriately protect against the chilling effect on anonymous First Amendment Internet speech that can arise when plaintiffs bring trivial defamation lawsuits primarily to harass or unmask their critics."
Once I get a hand on the case, I'll offer some more detailed analysis.