I've just this instant (really) come from updating my shared htaccess*, and would have been awfully annoyed if it turned out I'd missed one. Gosh, what a lot you can shave off the filesize by putting multiple Deny-froms in a single line, as in
Deny from 1.3 1.8 184.108.40.206/14 220.127.116.11/13 1.45 18.104.22.168/14
Deny from 22.214.171.124/14 126.96.36.199/13 188.8.131.52/14 184.108.40.206/12
Deny from 220.127.116.11/14 18.104.22.168/14 22.214.171.124/15 126.96.36.199/14 188.8.131.52/13
Deny from 184.108.40.206/15 220.127.116.11/14
(Not AWS, obviously, but same principle. Cut the size by 1/3, and I didn't even consolidate very much.)
* Multiple domains in the same userspace. You can't do everything in a shared htaccess-- and some things you wouldn't want to-- but consolidating the mod_auth_whatsit is a huge timesaver.