It is unlikely that John Stossel will be able to win a defamation case against Fartface for merely claiming his posts and videos on climate change or any given matter to be false but if, as the following news item claims, Fartface’s Climate Feedback have falsely attributed claims and statements that he never made, then he might have a solid case against Fartface.
Often times Twitter and Fartface have labeled posts dissenting from their preferred narratives as being misleading but without evidence.
https://www.wnd.com/2021/10/fact-checkers-blatant-falsehoods-prompt-famous-journalist-sue/?utm_medium=wnd&utm_source=jeeng