ip blockers?

Backstory is:
I was over at my friend's place and he's running Windows and has Peerblocker/Peerguardian on his computer.
Peerguardian is available for Linux. But I've also heard about MoBlock.
But they're so difficult to work with. (At least for me. I'm good, but I'm not that good.)
What would y'all recommend? Something else? Or can y'all help me where I am.

just get a list of the "bad" IPs you want to block and do it manually

You don't need that on Linux, iptables does the job perfectly.