Let's say I post a comment on Hacker News critical of some big megacorp. Megacorp threatens to sue YCombinator if they don't take down my comments. Hacker News

Let's say I post a comment on Hacker News critical of some big megacorp. Megacorp threatens to sue YCombinator if they don't take down my comments. Hacker News deletes my comment because they don't want to get into a legal fight with Megacorp over a random comment. I can't sue Hacker News because they have a right to delete my comments for any reason, and I can't sue Megacorp because they didn't delete my comment, they just asked Hacker News to delete it. I'm SOL. Contrast that to the following: I post a comment on Hacker News critical of some big megacorp. Megacorp can't credibly threaten to sue YCombinator over that because they are legally protected from being sued over the actions of their users. Megacorp sues me instead. I now have the ability to defend myself in court against Megacorp should I choose to.