Web Science and Digital Libraries Research Group

Figure 1: Snopes.com has no public captures on the Internet Archive’s Wayback Machine prior to October 2021. Snopes.com is a well-known fact checking website. It has been rated trustworthy by multiple rating organizations [1]. However, in 2021, BuzzFeed broke a story that, in fact, Snopes was plagued by plagiarized articles, and that authors were being told to plagiarize and then silently make updates to their articles after publication in the name of SEO . One of the byproducts of the BuzzFeed investigation is that there are no publicly available captures of Snopes.com in the Wayback Machine prior to 2021. Snopes’s official statement regarding this is that the founder, who was named responsible for the plagiarism, had a policy against Wayback captures; but, now that he was removed from duty, the board was going to change the policy going forwards. In fact, having no captures before 2021 means that the archives available give a more trustworthy historical view of Snopes.com than ex...

  The CDC ACIP vaccine recommendations page includes a human-readable (left) and machine-readable (right) last updated date.  In early 2025, US federal websites were undergoing rapid changes with the new presidential administration. In February 2025, we analyzed the rate of page deletions across administrations, and further analyzed the content of changed CDC pages in summer 2025. One surprising thing that we found was that while CDC pages contained a “last updated” date, many of the dates were incorrect: pages contained silent, unannounced updates, generally related to relevant executive orders. How does trustworthiness change over time? Silent, unannounced changes that do not match the last modified date of a webpage reduce the trustworthiness of the page. We can study three different change markers: the HTTP last-modified property , meta tags that contain last updated information, and text on the page that is viewable to the user containing update information. These mar...

Figure 1: A samhsa.gov page identified by the New York Times as removed under the second Trump administration On February 2, 2025, Ethan Singer ( @ethanpsinger ) published an article in the New York Times titled " Thousands of U.S. Government Web Pages Have Been Taken Down Since Friday ." Singer showed that over 8,000 webpages from at least a dozen federal agencies had been removed. The article exposed individual pages as well as entire sections of websites that had been taken down. In the full version of the article available to subscribers, Singer identified four limitations: This study only identified removed pages, not pages that stayed but changed. This study only covered the current administration on the specified day because they used live sitemaps. The live web can't be used to extend the study backwards to previous administrations. Continuing the analysis with this methodology for this administration as pages are restored or further removed requires constant mo...

Figure 1: Mementos from the Internet Archive's Wayback Machine showing the deletion of the entire LGBTQ youth resources page on the Virginia Department of Health website between  2023-05-31 and  2023-06-01 In July 2023, Virginia Governor Glenn Youngkin received national press for deleting webpages on the Virginia Department of Health website containing LGBTQ+ youth resources. This isn't the first time the Youngkin administration has deleted webpages: within one week of his inauguration, he deleted the Virginia Mathematics Pathways Initiative website . The Washington Post article from July 2023 also discussed additional webpages that had content removed in 2022. Journalists discovered these webpage changes through emails between state employees, but the emails didn't contain the website addresses. Without linking to mementos at a web archive, readers of the articles can't see the changes for themselves. Not linking to archived webpages in news articles is consistent w...

Figure 1: The Wayback Machine "Changes" tool showing the difference between George Santos's biography on December 19, 2022 and February 3, 2023. Deletions are highlighted in yellow and additions are highlighted in blue. Source:  https://web.archive.org/web/diff/20221219173515/20230203162225/https://georgeforny.com/about/ The Washington Post recently published the article, " See the evolution of lies in George Santos's campaign biography ." George Santos is a member of the U.S. House of Representatives in the 118th U.S. Congress. He has steadily removed claims from his website that have been proven to be false, such as holding a bachelor's degree from Baruch College. In the Washington Post article, the journalists used the Internet Archive's Wayback Machine to find and view previous versions of his webpage that included the false claims. To show change over time, they interspersed colored text boxes with the change text throughout the article. Previo...