Described as "the 26 words that created the internet," Section 230 of the Communications Decency Act catches a lot of flak for a piece of legislation that is largely responsible for online platforms' willingness to host discussion forums. In its absence, social media companies and message boards would likely return to the previous era of either allowing anybody to say anything, or else taking legal responsibility for every insult and slur posted on their platforms. That would probably mean the end of online discourse as we know it—which may be what happens if proposed bipartisan legislation "sunsets" Section 230.
