... include this one from ebay:
Can you tell me what the first and/or second characters are?
In case you weren't sure, here's a definition of 'captcha':
CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) A security device that requires human input rather and so prevents any kind of automated access to protected areas of a network. The most common online application is that of active tokens.
Note that this is from my book, Key Concepts in e-Commerce.
