https://www.techdirt.com/articles/20200805/07260045045/revisiting-common-law-liability-online-intermediaries-before-section-230.shtml

On February 8, 1996, President Clinton signed into law the Telecommunication Act of 1996. Title V of that act was called the Communications Decency Act, and Section 509 of the CDA was a set of provisions originally introduced by Congressmen Chris Cox and Ron Wyden as the Internet Freedom & Family Empowerment Act. Those provisions were then codified at Section 230 of title 47 of the United States Code. They are now commonly referred to as simply “Section 230.”

Section 230 prohibits a “provider or user” of an “interactive computer service” from being “treated as the publisher or speaker” of content “provided by another information content provider.” 47 U.S.C. § 230(c)(1). The courts construed Section 230 as providing broad federal statutory immunity to the providers of online services and platforms from any legal liability for unlawful or tortious content posted on their systems by their users.