Subliminal message in the sudoku square?

http://www.theguardian.com/global/2015/feb/27/subliminal-message-in-the-sudoku-square

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Sudoku no 3056 (G2, 27 February). Were we the only ones to be a little upset to see the pattern of the puzzle was a swastika?Hyder and Lea KhalilBrighton

• To answer Bob Frost’s question (Letters, 26 February) about “rougher than normal” sex. I suspect the answer is like the definition of “promiscuity”, which is: at least one more sexual partner than me.Martin JonesEastbourne, East Sussex

• Mr Harrison says bishops are elected by their cathedral chapters (Letters, 27 February). He fails to tell us who elects the chapters.Pete BibbySheffield