The term "13 knots" refers to the number of knots/coils in a hangman's noose; it is a symbol of white supremacy. The person who uses the name "Thirteen Knots" is sending out a dog whistle to others of his political ilk, to let them know he is one of them. Remember this when you evaluate his posts. The link to the video that Thirteen Knots uses is from "First TV," which is a fringe-right commentary network.