SAN FRANCISCO (CN) - A federal judge dismissed a lawsuit accusing Twitter of helping terrorists who killed two Americans overseas last year.
Tamara Fields, whose husband died in a terrorist attack in Jordan a year ago, sued Twitter in January, claiming the social network's refusal to block Islamic State propagandists contributed to her husband's death, and the deaths of four others, in Amman, Jordan, on Nov. 9, 2015.
Fields' husband was working as a contractor at a State Department-run facility when a lone gunman shot and killed him and another U.S. contractor, James Creach. ISIS claimed responsibility for the attack.
In March, Creach's wife and two children joined Fields as co-plaintiffs. U.S. District Judge William Orrick dismissed it with leave to amend in June, finding the plaintiffs had no evidence that the killer, 28-year-old police Capt. Anwar Abu Zaid, was recruited on Twitter or used the network to plan, carry out or raise money for the attack.
Orrick also concluded the Communications Decency Act of 1996 forbids holding publishers such as Twitter liable for content posted by its users.
On Friday, Orrick tossed the complaint for good, finding the plaintiffs could not overcome those legal hurdles by trying to sue Twitter for letting terrorists sign up for accounts or send private, direct messages, instead of focusing on the content they published publicly.
"Though plaintiffs allege that Twitter should not have provided accounts to ISIS, the unspoken end to that allegation is the rationale behind it: namely, that Twitter should not have provided accounts to ISIS because ISIS would and has used those accounts to post objectionable content," Orrick wrote in his 19-page ruling.
Lacking evidence of any direct link between Twitter activity and the attack, Orrick said that to allow the lawsuit would mean "any plaintiff could hold Twitter liable for any ISIS-related injury without alleging any connection between a particular terrorist act and Twitter's provision of accounts."
Such a theory of liability would persist indefinitely and make Twitter open to litigation over any and all future ISIS attacks.
"Such a standard cannot be and is not the law," Orrick concluded.
The plaintiffs argued that without Twitter giving ISIS a platform to spread propaganda, its "explosive growth" to become "the most feared terrorist group in the world would not have been possible."
In her original complaint, Fields cited statements by FBI Director James Comey, who said ISIS "perfected" its use of Twitter to inspire small-scale attacks, "crowdsource terrorism" and "sell murder."
In April 2015, Twitter updated its policy to prohibit threats of violence against groups and individuals and speech that encourages violence against others, including terrorism.
The company wrote in a blog post in February that it condemns the use of its platform to promote terrorism, and that it was increasing the size of its team and introducing new tools to address the problem more quickly and thoroughly.
It announced in August that it had suspended 250,000 accounts that promoted terrorism.
Orrick noted that the plaintiffs oversimplified the obligation they sought to impose on Twitter, to screen new accounts and private messages, an obligation even they acknowledged might have a "chilling effect" on Internet speech.
"These are not minor obligations, as they would require Twitter to fundamentally change certain aspects of its services and overturn its hands-off content-neutral approach," Orrick wrote. "The difference between treating them as a publisher for one type of content, as compared to no content, is substantial."
Neither Twitter's press office nor plaintiffs' attorney Joshua Arisohn, with Bursor Fisher in New York, immediately responded to phone calls and emails seeking comment Monday afternoon.