There's a time and a place for Regular Expressions ;) And, for that matter, for mod_rewrite. I've currently got
:: shuffling papers ::
Deny from 184.108.40.206/18 220.127.116.11/19 18.104.22.168/15 22.214.171.124/14 126.96.36.199/15 174.139
:: detour to look up ::
I've got 174.143 flagged as Rackspace, so you could easily go 14. Or, ahem, 188.8.131.52/15. The 174.34. neighborhood has a human ISP tucked in between two server farms so I can't just go 128-blahblah/17. I track server farms but don't generally lock them out until they become offensive. I don't have anything scrapeworthy, so why put the server to the extra work.
This particular botnet is pre-blocked because anyone who asks for anything in php-- except a handful of named pages-- gets an automatic 403 rather than defaulting to 404. It's the principle of the thing.
:: glancing at incoming mail and doing a double-take as I notice that son's iPhone has me down as "Mom Lastname" ::