[Skunkworks] Application level security using htaccess

Good people, Over the last couple of days, some rogue IPs and user agents have hammered an app of mine hosted on the cloud, has given me sleepless nights. This has led me to a sort of application firewall implemented using .htaccess rules... http://perishablepress.com/5g-blacklist-2012/ Anyone who has implemented this? And if so, any caveats I should be aware of? Below are the suspected rogue user agents: Python-urllib ZmEu libwww-perl core-project webcollage