[thephyber]

Have you considered the scale of the problem and how it would affect performance on your server?

Running pattern matching early in Node middleware that checks against a very very large block list will progressively choke every server that implements it.

If you decide to implement it, I recommend you look at how GeoMind API works. IP addresses are just displayed as octets for human readability; use the integer representation for faster+cleaner comparisons.