Sorry for interfering in this discussion, but if I understand this WebVisum.com site well (I admit I didn't read much), this mechanism could be used by jD as well. I understood WebVisum.com's servers support automatic anti-captcha techniques.

jD's customers could also solve each other's captchas. In exchange for the number of captchas they solve they get the same number of captcha resolutions from other members. That means that customers do not need to attend their downloads during the night or when they are away from their computers.

What do you think guys or did I steal someone's idea?