I spend quite a bit of time reading Wikipedia articles, and every once in a while I'll come across some phrase or sentence that doesn't jibe with common sense. So I'll dig through the article history and discover that it was added by some anonymous editor months ago with no supporting evidence and apparently nobody ever noticed. Sometimes other people have even come along later and copyedited the vandalism to correct capitalization or something without questioning the content itself.
Instances like these have taught me not to place full trust in the reliability of Wikipedia. Most of the examples below are rather obvious false claims, but there must be many other false claims that are not so easy to recognize and thus will remain unchallenged for longer.
Examples of long-lasting vandalism I've detected and reverted:
| Claim | Inserted | Reverted | Elapsed time |
|---|---|---|---|
| (Lead paragraphs of United Nations Security Council deleted) | 19:51, 6 February 2008 | 06:47, 18 February 2008 | 11 days, 11 hours |
| Imhotep was born 1/4/2650 BC, died 12/4/2600 BC, and claimed the title "Doctor." | 22:29, 14 August 2008 and 16:45, 16 August 2008 | 21:02, 22 November 2008 | 3 months, 6 days |
| One of the most famous uses of blowing a raspberry is to fart loudly. | 23:16, 10 April 2009 | 23:50, 25 May 2009 | 1 month, 15 days |
| (Lead paragraph of Null character deleted) | 20:13, 21 May 2009 | 07:17, 31 May 2009 | 9 days, 11 hours |
| According to legend, Alfred Bulltop Stormalong's ship became stuck in the Shuttup Channel. | 08:30, 2 September 2008 | 20:57, 31 May 2009 | 8 months, 30 days |
| The Polish government-in-exile commanded African armed forces operating outside Africa during the Second World War. | 05:14, 30 September 2009 | 01:32, 8 March 2010 | 5 months, 8 days |
| The name "Doha" comes from an Arabic word meaning "sticky tree." | 17:39, 18 January 2010 | 16:40, 12 July 2010 | 5 months, 24 days |
| Aurora, Nebraska receives 160 inches of rainfall each year. | 16:47, 29 April 2010 | 15:17, 16 July 2010 | 2 months, 17 days |
| A place in the United Arab Emirates was formerly known as "Bhubi Dhubhi." [Frighteningly, this little bit of vandalism actually made it onto the official Web site of the Embassy of the United Arab Emirates to Belarus! See [1].] | 01:41, 19 February 2009 | 13:37, 31 July 2010 | 1 year, 5 months, 12 days |
| Europe is a content. (In List of sets of four countries that border one another) | 19:50, 1 June 2010 | 06:44, 9 August 2010 | 2 months, 7 days |
| Lincoln Logs are made in China from rainforest wood. | 01:57, 14 July 2010 | 08:39, 3 September 2010 | 1 month, 20 days |
| Murder-holes are holes in ceiling gates. | 15:26, 21 October 2009 | 15:16, 30 December 2010 | 1 year, 2 months, 9 days |
| An alternative method for producing ethanol fuel is being developed that uses din mor algae. [Din mor is Danish for "your mom."] | 20:25, 3 April 2010 | 04:09, 6 January 2011 | 9 months, 2 days |
| Diego Rodríguez was born in the year 0001. | 15:59, 6 April 2011 | 19:56, 13 June 2011 | 2 months, 7 days |
| Lateritic bauxites are "silicitate bauxites"; bauxite is hardly ever strip mined because it is almost never found near the surface of the earth; about 10% to 12% of the world's dry bauxite production is processed first into alumina; and bauxite rocks can be classified as cosmetic, electric, or soundiferancic. [Several dates were also changed.] | 08:17, 14 June 2012 | 04:49, 3 September 2012 (fixed shortly afterward, 04:58, 3 September 2012) | 2 months, 20 days |
| Louis Hadski (chief editor) testified in Kitzmiller v. Dover Area School District. | 14:04, 20 October 2010 and 14:07, 20 October 2010 | 07:18, 14 September 2012 | 1 year, 10 months, 25 days |
| The first game of tic-tac-toe in America was played in 1856 at Theta Chi fraternity. | 03:47, 25 March 2014 | 22:50, 30 July 2014 | 4 months, 5 days |
| Marin Mersenne corresponded with Josh. | 21:24, 12 January 2012 | 12:48, 5 April 2016 | 4 years, 2 months, 24 days |
| WeBWorK green is a shade of green. | 21:40, 4 December 2015 | 01:24, 11 June 2016 | 6 months, 6 days |