For decades, big tech companies have leaned on a little-known law to avoid being held responsible for some of the most controversial content on their platforms -- Section 230 of the Communications Decency Act. They have invoked it repeatedly in court cases to dismiss potentially costly lawsuits over messages, videos and other content created by users. Under the law, tech companies can't be sued for trying to do the right thing, though the federal government can still sue platforms over criminal content. The original intent behind Section 230 was to nurture startups and entrepreneurs. One of its key architects, Sen. Ron Wyden, has said that without the law, "all online media would face an onslaught of bad-faith lawsuits and pressure campaigns from the powerful."