mod_defensible is an Apache 2.x module intended to block spammers using DNSBL servers.
It will look at the client IP and check it in one or several DNSBL servers and return a 403 Forbidden page to the client.
These details are provided for information only. No information here is legal advice and should not be used as such.
At one point, Open Hub analyzed source code for this project based on code location(s) available at that time. Since then, the code locations have been removed.