When you access the San Diego Sheriff's Who is in Jail website, you are asked to
type in a series of letters that you see in an image. The image contains letters
only and no numbers. If you can read the letters in the image, the web server
assumes you are human because computers presumably cannot read image text. This
feature is known as "CAPTCHA". It is an acronym that stands for "Completely
Automated Public Turing test to tell Computers and Humans Apart". We use CAPTCHA
to prevent outside automated systems from blocking your use of the website and
commercially exploiting our data.
We appreciate your understanding.