A group of 20,000 Israelis is suing Facebook for failing to clamp down on online incitement by Palestinian extremists, in a case that could have a profound impact on the way the social network operates.

“Facebook is fanning the flames of the current Palestinian intifada,” said the group’s lawyer, Tel Aviv-based Nitsana Darshan-Leitner, after she filed the lawsuit with the New York State Court this week.

She claimed that the social network had failed to adequately monitor or block Palestinian posts that encourage violence and accused it of “an outrageous abandonment of its obligations to the public”. As a result, Facebook is currently a “hub of terror,” she said.

Ms Darshan-Leitner directs Shurat Hadin, an Israeli legal advocacy group. Her 20,000 clients are demanding an injunction against Facebook that will require it to monitor itself and block “all racist incitement and calls for violence against Jews in Israel.” They are not asking for any money.

Just a day after the suit was filed, the battle became even more emotive. The lead plaintiff, injured in a terrorist attack, died, and his son accused Facebook of providing a platform for incitement.

“It cannot be that the world’s most powerful social network, whose influence is probably greater than that of heads of state… allows terrorists to call for the murder of innocent Jews,” Micha Lakin, the son of Richard Lakin, told Israel’s Channel 2. He added: “He died as a result of the same hatred he fought against his entire life.”

Richard Lakin, a 76-year-old teacher, originally from America, died on Tuesday, a fortnight after being shot in the head and stabbed in the chest during a terrorist attack on a Jerusalem bus.

Ms Darshan-Leitner said that what is needed is a change in mindset at Facebook. She argued that it is not enough for the company to delete posts only when it decides to uphold a complaint, and added that Facebook had the technology to monitor what is uploaded.

If Ms Darshan-Leitner wins the case, it is expected that Facebook will come under pressure to be more cautious over what content it permits. Facebook refused to comment.