Section 230 is a law which designates some sites like Facebook as platforms instead of publishers where they cannot be held liable for any illegal content posted
But Facebook has also conducted publishing in the form of monitoring content and shadowbanning people and stuff, which has been unfairly defended as being okay since it's a private company, even though Facebook is a platform. So they basically get the best of both worlds with no consequences, which is wrong
Facebook basically entirely hinges on section 230 right now so if it got reformed that would be bad for it