The U.S. Supreme Court on Thursday unanimously rejected terrorism lawsuits against Google, Twitter and Facebook and refused to revisit the broad immunity the tech companies have long enjoyed under a law known as Section 230.

The court said the surviving family members of terror victims have not presented viable claims that the social media platforms aided and abetted ISIS in violation of the Anti-Terrorism Act. In their lawsuits, the plaintiffs alleged that the companies allowed ISIS terrorists to use their platforms to recruit and radicalize new members, leading to deadly attacks in Paris and Turkey.