This page is also available in: עברית (Hebrew)

The lawsuit, filed in a federal New York court on Sunday and announced Monday, was on behalf of the relatives of three US nationals who were killed by ISIS in Belgium and Paris.

Familes of two American victims of Islamic State terrorist attacks in Europe, represented by Shurat Hadin, have sued Twitter in a civil action for terrorism, charging that the social media giant allowed the terror group to proliferate online.

The lawsuit, filed in a federal New York court on Sunday and announced Monday, was on behalf of the relatives of three US nationals who were killed by ISIS in Belgium and Paris.

In the lawsuit, the plaintiffs seek monetary compensation “in amounts to be determined at trial,” arguing that Twitter “has violated, and is continuing to violate, the [US] Anti-Terrorism Act.”

The families of New York siblings Sascha, 26, and Alexander Pinczowski, 29, who were killed in a metro bombing claimed by ISIS in Brussels on March 22, are one of the lawsuits plaintiffs.

Family members of Nohemi Gonzalez, 26, an American student killed by ISIS in Paris in the November 13, 2015, attack that claimed the lives of at least 130 people, are the lawsuits other plaintiffs.

In the complaint, the plaintiffs charge that the social media company played “a uniquely essential role in the development of ISIS’s image, its success in recruiting members from around the world, and its ability to carry out attacks and intimidate its enemies.”

The plaintiffs further accuses Twitter of “having knowingly provided material support and resources to ISIS.”

According to the plaintiffs’ lawyer and Shurat Hadin Director Nitsana Darshan-Leitner, “This is the first lawsuit to document Twitter’s key role in the rise of ISIS to become the most feared terrorist organization in the world, and to detail how ISIS used Twitter specifically in connection with two of the worst terror attacks in Europe’s recent history.

“Among social media platforms, Twitter has most brazenly refused to cut off its services to terrorists, taking the position that ‘the tweets must flow’ even if it means assisting in mass murders.”

To date, the lawsuits against Twitter have not reaped significant fruits.

A January 2016 lawsuit by Tamara Fields, wife of a private American military contractor killed by a terrorist in Jordan, was dismissed. A June 2016 lawsuit filed by Reynaldo Gonzalez, father of Nohemi Gonzalez, who was murdered by ISIS terrorists in Paris in November 2015, was amended after concerns that it would be dismissed.

Shurat Hadin and others hope that the Anti-Terrorism Act lawsuits have a better chance of working to get around the Communications Decency Act, which has insulated Facebook and Twitter from incitement lawsuits, with a conceptual jump to view the social media platforms not merely as message boards for terrorists, but as providing concrete material logistical support.

In December, Twitter, along with social media giants Facebook and YouTube, announced that they were taking steps to combat the spread of online terrorist content.

According to the companies, they are working to create a shared industry database of “hashes,” unique digital “fingerprints,” for violent terrorist imagery, terrorist recruitment videos or images that have been removed from their services that they will then share with one another.

The move came after Israel and other countries complained that social media companies had not been doing enough to reduce the amount of terrorist-related content.