Hacker News new | comments | show | ask | jobs | submit login

Look into MaxMind MinFraud. In addition to providing a 'risk score' for your online orders, it's also a kind of collective blacklist like you described. Any MaxMind customer can report an IP or e-mail address as associated with a fraudulent order, and any other MaxMind customer who recently scored an order with the same IP or e-mail gets a warning about the increased risk.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact