This bait-and-switch trick began on 4chan as a spin-off of an earlier joke known as duckrolling. On April 1st, 2008, every video on YouTube's front page redirected to the Rickroll music video. The prank has extended beyond the web to playing the video or song disruptively in public places, like at the Macy's Thanksgiving Day Parade in 2008 when Astley made a surprise appearance.
32. The Rickroll