The family of 23-year-old student Nohemi Gonzalez, the only American killed during the ISIS terrorist attack in Paris last fall, filed a lawsuit last week against Facebook, Twitter and Google for supplying “material support” to terrorists.

The victim’s father, Reynaldo Gonzalez, wrote in a complaint to the court that these sites “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.”

Facebook defended itself with a statement, saying that there is “no place” for terrorism or content that promotes it on its pages. Indeed, the three platforms may be protected by the Communications Decency Act, which says that websites are not liable for the content that users post. However, the victim’s family argues that the “support” Facebook provides is worthy of a lawsuit.

“Google, Twitter and Facebook provide infrastructure and material support for ISIS to conduct terrorist activity,” the attorney representing the victim’s family, Keith Altman, said. “These companies are not doing a good enough job from keeping the terrorists from using their network… It’s like whack-a-mole. I don’t think ISIS could sustain their operation without these social networks.”

It’s true that ISIS has a huge presence on social media, and it has proven hard for these sites to keep up with policing terrorist content. This suit faces an uphill battle because of existing laws that protect websites from their own users, but hopefully the victim’s family is able to find some form of justice anyway.