The most adorable spambot killer ever

Enter Oli, and his moment of "thinking outside the text box." While computers are getting better and better at optical character recognition, one thing that they still have great difficulty doing is recognizing the contents of pictures. Oli, who runs a web site called ThePCSpy.com, realized that a computer would have a great deal of difficulty in telling the difference between different types of fuzzy animals. So he came up with KittenAuth, a test that requires the user to identify which three out of nine pictures contain kittens. The "3 in 9" grid leaves the poor spambot with only a one in 84 chance of randomly picking the right answer. Larger grids or number of picks can make the chances lower still.