WOTY Nomination: Captcha

[Grant Barrett]

This WOTY nomination is a late entry, coming into common usage only
recently: captcha. A captcha distinguishes a human from a machine.
Usually these devices are used to prevent repeated automated logins to
web sites, such as free email services, which might be abused by
spammers or others of ill intent.

One mention:

http://www.theregister.co.uk/content/6/28694.html

The word is supposedly an acronym for Completely Automated Public
Turing tests to tell Computers and Humans Apart).