"I suggested that Substack’s day of reckoning may still lie ahead. The bigger Substack gets, the more ideologically diverse its author pool becomes, the greater the chances for highly inflammatory, potentially harmful content. (Imagine, say, a QAnon Substack?) “I think as Substack grows, the tests will become more frequent and more difficult,” said McKenzie. “That’s unavoidable. This is not ever going to be a not-difficult problem."