Anti-malware providers got good news today from the U.S. Ninth Circuit Court of Appeals in Seattle, Wash.

Readers of this blog may remember the lawsuit that Zango filed against Kaspersky back in 1997 for blocking its software. As we reported, Zango's case against Kaspersky suffered a severe setback when the Washington State Superior Court handling the case granted Kaspersky's motion for summary judgment on the grounds that Kaspersky, as an "interactive computer service" provider, enjoyed immunity from such lawsuits under section 230 of the "Communications Decency Act" (CDA, 1996) (link here).

We hailed that decision and promptly signed on to the amicus brief filed by the Center for Democracy and Technology with the Ninth Circuit Court of Appeals in response to Zango's appeal of the original decision (link here).

An appellate court judge has upheld a judge's decision to throw out a lawsuit alleging that software from a leading anti-virus firm illegally blocked programs from Zango, a now-defunct provider of online games that previously settled with the federal government over adware charges.

The 9th U.S. Circuit of of Appeals ruled that Russia-based Kaspersky Lab was not in violation of the law when it identified some Zango software as malicious and blocked access to users, according to a statement Tuesday from Kaspersky. The company is protected under the Communications Decency Act of 1996, which bars it from being held liable for placing restrictions on materials it deems inappropriate, the court ruled.

The court ruled that Kaspersky "is entitled to Good Samaritan immunity" because it classified Zango software as spyware and adware, according to Kaspersky.

Zango had sued Kaspersky to force it to classify Zango problems as nonthreatening. But in September 2007, U.S. District Court Judge John Coughenour, sitting in Seattle, dismissed the lawsuit on the same grounds as the appeals court.

Zango, which shut its doors earlier this year, settled in 2006 with the Federal Trade Commission for $3 million and was barred from downloading adware without users' consent. The agency said Zango offered customers free web content, such as screensavers, games and peer-to-peer file-sharing software, without telling them it also contained adware. The adware, provided by third-party affiliates, allegedly monitored the consumers' browsing habits in order to display targeted pop-up ads.