What Is CAPTCHA (Besides An Online Annoyance)?
CAPTCHAs were invented to stop spamming robots from infiltrating forums, ticket-buying websites, and other areas of the web. The most familiar CAPTCHAs use distorted text that a user must type into a box, but newer tests can incorporate images and even games.
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from Are You a Human
Key Facts In This Video
In 1864, people were upset about an unsolicited telegram advertising a dental practice, one of the very first pieces of spam. (0:04)
In 1998, Yahoo was besieged by millions of spambots setting up email accounts. (0:33)
Computers have become better at reading CAPTCHAs, prompting CAPTCHAs to become more difficult. (1:05)