Perhaps a bug. Chrome on my Galaxy S3 showed the white's queen (and I believe bishop) as the color of the background. This was a problem because they were on a

Perhaps a bug. Chrome on my Galaxy S3 showed the white's queen (and I believe bishop) as the color of the background. This was a problem because they were on a grey tile. When I first tried the captcha, the board arrangement looked like white had a king and a few pawns in the lower right and that black had two queens and a bishop in addition to their king at the top of the board. The white, according to my incorrect reading of the board, instantly looked like it was in check, but the captcha was saying that it was white's turn to put black into checkmate. I was completely confused and tried multiple times to move the "black" queen into a position that would checkmate white believing the captcha text to just be incorrect or misleading. After a couple failed attempts, I realized the queen I was trying to move was grey, not black, and then I solved the captcha. In this case, the captcha took way too long because the pieces were hard to distinguish and the captcha text was unclear. I think that captchas should be something you can do near instantaneously. However, I really like the concept and the trying of a new approach. I've had success implementing what I feel to be very simple captchas: solve simple arithmetic problems. I'm sure a parser could be created simply enough that would solve them, but I have had zero forum spam in a couple of small forums that use it.