Two lawsuits seeking to hold Facebook responsible for terrorism groups' use of the social media platform have been dismissed by a federal judge.

The plaintiffs in Force v. Facebook, filed last year, are the families and estates of US citizens who were killed by Hamas, a Palestinian organization that is considered a terrorist group by the US government. The plaintiffs group also included one victim who was injured but survived.

They sought $1 billion in damages, claiming (PDF) that by providing social media services to Hamas, Facebook had violated the US Anti-Terrorism Act, which forbids the "provision of material support" to officially designated terrorism groups. The plaintiffs complained that Facebook's approach to expunging Hamas material from the Web was "piecemeal and inconsistent."

Yesterday, US District Judge Nicholas Garaufis ruled (PDF) that Facebook was protected by Section 230 of the Communications Decency Act, which generally prevents online platforms from being held liable for the actions of their users.

The plaintiffs in this case had unsuccessfully tried to push past Section 230 by claiming that Facebook was effectively "the publisher or speaker of" third-party content. That exception has allowed some lawsuits against Web platforms when the online companies have exercised "traditional editorial functions," such as "deciding whether to publish, withdraw, postpone, or alter content."

Section 230 "prevents courts from entertaining civil actions that seek to impose liability on defendants like Facebook for allowing third parties to post offensive content or harmful content or failing to remove such content once posted," Garaufis held.

A separate lawsuit was brought by some 20,000 residents of Israel who said that Facebook's failure to expunge Hamas put them at increased risk of a terror attack. The judge threw that lawsuit out as well, saying that they showed at most "a general risk of harm" to the plaintiffs, because they resided in Israel.

"While the court does not question the sincerity of the Cohen Plaintiffs' anxieties, their subjective fears cannot confer standing absent a sufficient showing of the risk of future harm," Garaufis wrote.

Robert Tolchin, a lawyer representing plaintiffs in both the Cohen and Force cases, told the Reuters news agency that the judge misapplied the Anti-Terrorism Act and that his clients plan to appeal "major errors in the decision."

"There is a clash between statutes that the court needed to reconcile but ignored," he said.

"[T]here is no place on Facebook for groups that engage in terrorist activity or for content that expresses support for such activity, and we take swift action to remove this content when it's reported to us," a Facebook spokesperson said. "We sympathize with the victims and their families."

Listing image by Force v. Facebook complaint