In 1995, a New York State Court ruled that Prodigy, an internet service provider, was responsible for what was posted on its message boards, and as a result, Prodigy had to devote enormous resources to taking down potentially problematic content.
In response, Congress passed Section 230 of the Communications Decency Act, which says that providers and users of interactive computer services (like Twitter) cannot be held liable for the content posted by other information content providers.
Since 1996, the modern internet has been defined by a sweeping law that prevents tech companies such as Facebook and Google from being held responsible for the content posted on their sites.
This week, the Supreme Court heard arguments in a case that could take that legal immunity away.
Guest: Adam Liptak, who covers the Supreme Court for The New York Times.