The line comes from The Lord of the Rings: The Fellowship of the Ring from 2001, where Gandalf, played by Ian McKellen, confronts the Balrog on the Bridge of Khazad-dum. The moment became one of the most quoted scenes in fantasy cinema and later spread widely as a meme image, GIF and sound clip online. Shortened to YSNP in many soundboard titles, the audio is now used far beyond the film for any situation involving blocking, guarding or dramatically refusing entry.