For decades, the Motion Picture Production Code (or Hays Code) strictly regulated what could be shown on screen, including a ban on anything considered 'indecent.' Surprisingly, this included the sight and sound of a toilet flushing. Alfred Hitchcock’s 1960 masterpiece 'Psycho' famously broke this taboo. In a pivotal scene, Janet Leigh's character flushes a piece of paper down a toilet to dispose of evidence. This was the first time in American cinema history that a toilet was shown and heard flushing. Hitchcock had to fight the censors to keep the shot, arguing it was essential for the plot. While seemingly minor today, it was a massive shock to audiences at the time and signaled the beginning of the end for the restrictive Hays Code, leading to the more permissive rating system Hollywood uses today.