Discussion Question: What's the Biggest Piece of Disinformation Circulating Right Now? What's the Best Way to Debunk It?

In an attempt to help Brad DeLong and others "for when [we are] surprised, as [we] will be, by an unexpected question from an unexpected direction while talking to reporters, phone callers, passers-by, radio interviewers, cable TV interviewers, etc.":

What's the biggest piece of disinformation circulating right now, and what's the best way to debunk it?

This asks about the biggest piece of disinformation, but identifying potential "surprise" pieces of disinformation that reporters and others might ask about and how to debunk them would also be very helpful.

Click on the question to answer.  (The answers to previous questions are in the outermost sidebar.)