Cisco Access List BlackList IPs

Well, blacklists are dynamic. Whatever you enter today might not be correct tomorrow. So personally I don't think it's a good idea to enter a static blacklist, you'll need to update that every day :-~ Furthermore, you normally set up a router or firewall to block all incoming traffic except return traffic to outgoing requests from inside hosts so everything (including 'malicous' IPs) should be blocked.
Most blacklists are email/spam related so those IPs won't try to access the network, they just spam your mailserver.

But perhaps I'm not getting the picture of what you are trying to do excactely, could you elaborate a bit?

I guess I can do that .. for only established connections from inside out and allowed certain ones. I would git that a try, but are there any list from like known hackers, information stealers, or botnet ? I was looking for a list like that :)

ok sounds good, thanks guys, i will use the only allow established connections. I bet that would be better on router resources since it wont have to try to match so many entries on an access list.