Using CAPTCHA As An Anti-Bot Test
April 26th, 2006Have you ever wondered how sites create those blurry images of numbers and letters to prevent automated scripts from submitting forms? Wikipedia has a great list of resources for creating your own.
CAPTCHAs are used to prevent bots from using various types of computing services. Applications include preventing bots from taking part in online polls, registering for free email accounts (which may then be used to send spam), and, more recently, preventing bot-generated spam by requiring that the (unrecognized) sender pass a CAPTCHA test before the email message is delivered.