Blocking Server Farm Range

[orthohin]

What's the consensus here regarding protecting a web server against fake searchbots, scrapers and/or infected hosts on dedicated IPs? Do you block individual addresses (or at most the class C range) OR do you apply rules to block complete ranges known to belong to hosting companies?

Thanks

[Sogo7]

Fake search-bots  are easy ..

the IP ranges where Googlebot, yahoo and MSN offically come from are well documented so spotting a request with a bogus User Agent String is ridiculoulsy simple. There is no need to actually have the htaccess file block that particular IP,  instead just feed it random garbage text or have the page execute a die() command if your on a PHP server.