Custom Image Captcha makes it much harder for bots to solve your Captchas
Custom Image Captcha makes it much harder for bots to solve your Captchas, while at the same time making it easier for users. It also allows you to add an extra customized touch to your forum.
Many of the popular CAPTCHA systems fail, simply because they are popular, and so become an easy target for bots to train against. However, Custom Image Captcha can not suffer this same fate, since every forum can use unique image sets.