How do I block proxies/vpns/datacenters?

[Gpizzle]

Ok so we all know hackforums blocks all kinds of countries and stuff.
I want to know the following.

1. how did omni get all the data center ip ranges
2. whats the best way to block it all?

I'll pay someone to do this for me.

[TalishHF]

Google it, im sure you can just block certain countries through cPanel.