The family of an American student killed by the Islamic State during a November 2015 attack in Paris is suing Twitter, Facebook and Google for providing, “material support” to the terrorist group.

Nohemi Gonzalez, 23, was the only American victim among 130 killed in coordinated attacks at a Parisian soccer stadium and concert venue.

In a complaint filed this week in the U.S. District Court of Northern California, her father, Reynaldo Gonzalez, argues the three platforms “have knowingly permitted the terrorist group ISIS to use their social networks as a tool for spreading extremist propaganda, raising funds and attracting new recruits.”

The Islamic State, also known as ISIS, has active presences on both Facebook and Twitter, though the platforms have cracked down in the past and deactivated accounts affiliated with terrorist organizations.

Google is named in the suit, filed this week, as the owner of YouTube, which the Islamic State has used to post propaganda including videos of executions.

“Google, Twitter and Facebook provide infrastructure and material support for ISIS to conduct terrorist activity,” said Keith Altman, attorney for the family. “These companies are not doing a good enough job from keeping the terrorists from using their network.”

In some cases, the complaint says, the social networks place ads next to Islamic State content and share revenue with the terrorist group generated from those ads.

The platforms, though, could be shielded from the suit under provisions of the 1996 Communications Decency Act, which does not hold websites liable for content users post.

“[Social networks] can censor more or less anything they want and it also have incredible abilities to leave up as much as they wants to leave up,” said Ryan Calo, professor of law at the University of Washington and co-director of the school’s Tech Policy Lab.

In a statement on its website, Facebook said there was “no place for terrorists or content that promotes or supports terrorism,” but also said the suit was “without merit” and pledged to defend itself “vigorously.”

Twitter also said the suit was “without merit.”

“Violent threats and the promotion of terrorism deserve no place on Twitter and, like other social networks, our rules make that clear,” a spokesman said.

Google declined to comment on pending litigation and defended its “strong track record of taking swift action against terrorist content.”

But Altman said the networks do far too little police their users. When a site deactivates one account, another pops back up to take its place without much oversight.

“It’s like whack-a-mole,” he said. “I don’t think ISIS could sustain their operation without these social networks.”

The first conference set for the case is in September.

The case is Gonzalez et. al v. Twitter, Inc., Google, Inc., and Facebook, Inc.

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