This plugin checks if a visitor is listed on httpBL.abuse.ch. httpBl is a DNSBL which can be used to blocks access from IPs which are:
- Known source of Hacking activities (mostly script kiddies)
- Source of Remote File Inclusion attacks (RFI)
- Hijacked webserver
- Scanning drones
- Source of referer Spam
For more information take a look at the FAQ.