The Supreme Court spent two days debating whether Big Tech should be held liable for fueling the growth of terrorism online.

The broadness of the protections provided in Section 230 of the Communications Decency Act of 1996 has come into question. The law says sites like YouTube, Google, Facebook, and Twitter are immune to legal claims concerning content posted by their users.

In Tuesday’s case – Gonzalez v. Google – Google and its subsidiary, Youtube, were questioned in relation to the murder of Nohemi Gonzalez by Islamist militants.

Gonzalez’s family alleged that Youtube’s recommendation feature “assists ISIS in spreading its message and thus provides material support to ISIS.”

In the case on Wednesday, the American relatives of a man killed in the 2017 Reina attack in Istanbul sued Twitter under the Anti-Terrorism Act.

His family is seeking damages on the basis that the “defendants’ social media platforms allowed ISIS to post videos and other content to communicate the terrorist group’s message, to radicalize new recruits, and to generally further its mission.”

A key stipulation is whether the companies provided “substantial assistance” to an “act of international terrorism,” thus allowing the relatives to maintain their suit.

Justice Clarence Thomas remarked on the case: “If we’re not pinpointing cause and effect or proximate cause for specific things then it would seem that every terrorist act that uses this platform would also mean Twitter is an aider and abettor in those instances.”