Lawyers may differ in their assessments of Section 230 of the Communications Decency Act (CDA), but one thing is clear: The law has been a powerful shield for internet companies in fending off liability suits. Now, the scope of Section 230 is being redefined by Congress, one of the few times that has happened since 1996.

The House of Representatives at the end of February passed its version of a bill known as FOSTA—or Allow States and Victims to Fight Online Sex Trafficking Act (H.R. 1865)—and the Senate is on track to approve it later this month. Here’s an overview of how the legislation has evolved and what it might mean for litigation in the future.