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 file photograph dated 07 January 2006 and released by Greenpeace, showing the Yushin Maru, a factory ship in a Japanese whaling fleet, injuring a whale with it's first harpoon attempt. A UN court in The Hague on 31 March 2014 halted Japan's much-criticized whaling programme, ruling that it contravenes a 1986 moratorium on whale hunting. Japan must end its 'research whaling' programme, the International Court of Justice (ICJ) said. Japan said the programme was for scientific research and permitted under international conventions. Australia had brought the case to the ICJ in 2010, charging that Japan was breaching international law by killing hundreds of whales every year for commercial purposes. Japan was “deeply disappointed” by the ruling, an unnamed government official was quoted by the Kyodo News agency as saying. But the official said Japan would stand by the ruling. (Photo by Kate Davison/EPA)

In this March 15, 2012 file photo, a Chinese woman poses for photos near a sculpture depicting a Chinese yuan note at an art district in Beijing, China. China devalued its tightly controlled currency on Tuesday, August 11,2015, following a slump in trade, triggering the yuan's biggest one-day decline in a decade. The central bank said the yuan's 1.3 percent fall was due to a change aimed at making its exchange rate controls more market-oriented. But any change raises the risk of tensions with China's trading partners. (Photo by Ng Han Guan/AP Photo)

In this file photo taken on Sunday, August 2, 2020, Sviatlana Tsikhanouskaya, candidate for the presidential elections greets people waving old Belarus flags during a meeting to show her support, in Brest, 326 km (203,7 miles) southwest of Minsk, Belarus. Belarus’ authoritarian President Alexander Lukashenko faces a perfect storm as he seeks a sixth term in the election held Sunday, Aug. 9, 2020 after 26 years in office. Mounting public discontent over the worsening economy and his government’s bungled handling of the coronavirus pandemic has fueled the largest opposition rallies since the Soviet collapse. (Photo by Sergei Grits/AP Photo)

Lance Cpl. Blas Trevino of the 1st Battalion, 5th Marines, shouts out as he is rescued on a medevac helicopter from the U.S. Army's Task Force Lift “Dust Off”, Charlie Company 1-214 Aviation Regiment after he got shot in the stomach outside Sangin, in the Helmand Province of southern Afghanistan on June 11, 2011. The Army's 'Dust Off' crew needed two attempts to get him out, as they were fired upon and took five rounds of bullets into the tail of their aircraft. (Photo by Anja Niedringhaus/AP Photo/File)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)

In this Sunday, August 5, 2012 file photo South Africa's Oscar Pistorius starts in the men's semi-finals of the 400-meter in the Olympic Stadium at the 2012 Summer Olympics, London. Pistorius could be granted parole on Friday, Nov. 24, 2023 after nearly 10 years in prison for killing his girlfriend. The double-amputee Olympic runner was convicted of a charge comparable to third-degree murder for shooting Reeva Steenkamp in his home in 2013. He has been in prison since late 2014. (Photo by Anja Niedringhaus/AP Photo)

A terminally ill patient raises his arm in a hospice for those dying of AIDS at the Buddhist temple Wat Prabat Nampu in Lopburi province, north of Bangkok November 30, 2014. From 1992, the temple has provided housing for HIV positive patients and palliative care for those in the final stages of the AIDS disease. Data from 2013 estimates Thailand has 450,000 people living with HIV/AIDS, but only 353,000 have access to life-saving antiretroviral drugs. (Photo by Damir Sagolj/Reuters)