Supreme Court justices appeared broadly concerned Tuesday about the potential unintended consequences of allowing websites to be sued for their automatic recommendations of user content, highlighting the challenges facing attorneys who want to hold Google accountable for suggesting YouTube videos created by terrorist groups.

For nearly three hours on Tuesday, the nine justices peppered attorneys representing Google, the US government and the family of Nohemi Gonzalez, an American student killed in a 2015 ISIS attack, with questions about how the court could design a ruling that exposes harmful content recommendations to liability while still protecting innocuous ones.