Julian A. Biggs analyzes legal opinions concerning standards applied in various cases involving unmasking anonymous commenters on the web. He writes, in part, about Quixtar:
The Court of Appeals’ opinion provides valuable guidance to trail level courts as to which test should apply in any particular case.
In particular, it asserted two important governing principles: that the major driver in that choice should be the nature of the anonymous speech at issue; and that anonymity warrants far less First Amendment protection — and a less demanding test for the plaintiff — when it covers commercial rather than non-commercial speech. (See Quixtar at *6, citing Perry v. Schwarzenegger, 591 F.3d 1147, 1160-61 (9th Cir.2010).)
Read his entire article on Law.com.