241543903 (a.k.a “Heads in Freezers”) is a numerical keyword associated with a photo meme that involves people taking pictures with their heads in the freezer & sharing them online. By tagging a series of image files with a cryptic number, a high level of search engine optimization can be easily achieved. As a result, typing “241543903” into image search engines like Google Images successfully yields pages after pages of pictures showing people’s heads in freezers.
In 2009, David Horvitz started the “Heads in Freezers” meme. Participants took photos of their heads in freezers, tagged them with “241543903” and uploaded them to social media sites like Tumblr.

A three wheeled “cabin” scooter manufactured by German aircraft engineers Messerschmitt & Co at factories in Regensburg. (Photo by Hans Enzwieser/BIPs/Getty Images). 1955

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

The sun rises over the Baltic Sea and a pier with a tea house in Timmendorfer Strand, Germany, Sunday, August 7, 2022. (Photo by Michael Probst/AP Photo)

A Lion peers out of a window on Fitzwilliam Square, Dublin, Republic of Ireland on October 25, 2022. (Photo by Dara Mac Dónaill/The Irish Times)

A fan of Canada takes a selfie with former Miss Croatia Ivana Knoll who attends the game during the FIFA World Cup Qatar 2022 Group F match between Croatia and Canada at Khalifa International Stadium on November 27, 2022 in Doha, Qatar. (Photo by Matthew Ashton – AMA/Getty Images)

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Moroccans gather to celebrate Morocco's win over Spain in a World Cup soccer match played in Qatar, in Rabat, Morocco, Tuesday, December 6, 2022. (Photo by Mosa'ab Elshamy/AP Photo)