Mobile internet users are prompted to solve the same text-based CAPTCHAs used on desktop computers, but it has been found that mobile devices are poorly suited for solving these text-based CAPTCHA tests. These tests are more difficult on mobile devices because text is time-consuming to enter and the size of mobile displays can make the CAPTCHA hard to see and interpret. We introduce a new CAPTCHA mechanism called Picturesque specifically designed for mobile phone devices, based on image recognition techniques.