This site is under construction and is both very incomplete and subject to change.
The current cannonical site for documentation is here.

Introduction

There are many plugins that use a database to check if an IP address is malicious after the IP connects, and of course fail2ban stops repeated attacks, but what if bad IPs could be blocked before they attack?

By working collaboratively – sharing attack data – WP fail2ban Blocklist does exactly that.

The Blocklist Network Service (BNS) collects attack data from participating sites, performs some analytical magic, and sends back a list of IPs that are attacking sites now but haven’t yet attacked that site. In other words, each site periodically gets a unique list of IPs to block preemptively.