Editing CAPTCHA (section)

== History ==
Since the 1980s–1990s, users have wanted to make text illegible to computers.<ref name=":1" /> The first such people were [[Hacker culture|hackers]], posting about sensitive topics to [[Internet forum]]s they thought were being automatically monitored on keywords. To circumvent such filters, they replaced a word with look-alike characters. ''HELLO'' could become {{nowrap|<code>{{!}}-{{!}}3{{!}}_{{!}}_()</code>}} or {{nowrap|<code>)-(3££0</code>}}, and others, such that a filter could not detect ''all'' of them. This later became known as [[leet]]speak.<ref>{{Cite web|title=h2g2 – An Explanation of l33t Speak – Edited Entry|url=http://www.bbc.co.uk/dna/h2g2/A787917|access-date=2015-06-03|website=h2g2|date=16 August 2002 |archive-date=6 September 2011|archive-url=https://web.archive.org/web/20110906114613/http://www.bbc.co.uk/dna/h2g2/A787917|url-status=live}}</ref>

One of the earliest commercial uses of CAPTCHAs was in the Gausebeck–Levchin test. In 2000, idrive.com began to protect its signup page<ref>{{Cite web|title=idrive turing signup page|url=https://drive.google.com/open?id=0BzbOLm20p6CrUE1SSXp5Zjl2MW8|access-date=2017-05-19|website=Google Drive|archive-date=15 March 2023|archive-url=https://web.archive.org/web/20230315233241/https://accounts.google.com/v3/signin/identifier?dsh=S-569764738%3A1678923161301090&continue=https%3A%2F%2Fdrive.google.com%2Fopen%3Fid%3D0BzbOLm20p6CrUE1SSXp5Zjl2MW8&followup=https%3A%2F%2Fdrive.google.com%2Fopen%3Fid%3D0BzbOLm20p6CrUE1SSXp5Zjl2MW8&ifkv=AWnogHfb-QQLSi-KGh4vgzje6iZGJ1BZZvpaKSlXZLsXVSfSHlafPjo8v6B9qJTV2nuxzahDQYGTtw&osid=1&passive=1209600&service=wise&flowName=GlifWebSignIn&flowEntry=ServiceLogin|url-status=live}}</ref> with a CAPTCHA and prepared to file a patent.<ref name=":1">{{Cite web|url=https://drive.google.com/open?id=0BzbOLm20p6CrOS1mWEhITGJ4d2s|title=idrive turing patent application|access-date=2017-05-19|archive-date=15 March 2023|archive-url=https://web.archive.org/web/20230315233244/https://accounts.google.com/v3/signin/identifier?dsh=S956306740%3A1678923164278227&continue=https%3A%2F%2Fdrive.google.com%2Fopen%3Fid%3D0BzbOLm20p6CrOS1mWEhITGJ4d2s&followup=https%3A%2F%2Fdrive.google.com%2Fopen%3Fid%3D0BzbOLm20p6CrOS1mWEhITGJ4d2s&ifkv=AWnogHfWh9qH38C8IGelcYVq9WSJcqP6Q30eP1Bba6t1EcfIlDb1n3eZMtAJSv1IRxdTdxgTsu8r0A&osid=1&passive=1209600&service=wise&flowName=GlifWebSignIn&flowEntry=ServiceLogin|url-status=live}}</ref> In 2001, [[PayPal]] used such tests as part of a fraud prevention strategy in which they asked humans to "retype distorted text that programs have difficulty recognizing."<ref name=stringham2015>{{cite book |last1=Stringham|first1=Edward P |title=Private Governance : creating order in economic and social life |publisher=[[Oxford University Press]] |year=2015 |page=105 |isbn=978-0-19-936516-6 |oclc=5881934034 }}</ref> PayPal co founder and CTO [[Max Levchin]] helped commercialize this use.

A popular deployment of CAPTCHA technology, [[reCAPTCHA]], was acquired by Google in 2009.<ref>{{cite web |title=Teaching computers to read: Google acquires reCAPTCHA |url=https://googleblog.blogspot.com/2009/09/teaching-computers-to-read-google.html |url-status=live |archive-url=https://web.archive.org/web/20190831195346/https://googleblog.blogspot.com/2009/09/teaching-computers-to-read-google.html |archive-date=31 August 2019 |access-date=29 October 2018 |website=Google Official Blog}}</ref> In addition to preventing bot fraud for its users, Google used reCAPTCHA and CAPTCHA technology to digitize the archives of ''[[The New York Times]]'' and books from Google Books in 2011.<ref>{{cite news |last1=Gugliotta |first1=Guy |date=28 March 2011 |title=Deciphering Old Texts, One Woozy, Curvy Word at a Time |website=The New York Times |url=https://www.nytimes.com/2011/03/29/science/29recaptcha.html |url-status=live |access-date=29 October 2018 |archive-url=https://web.archive.org/web/20171117172409/http://www.nytimes.com/2011/03/29/science/29recaptcha.html |archive-date=17 November 2017}}</ref>