apache module:
http://www.cohprog.com/mod_bandwidth.html
should work with apache 2.0
or htaccess should block most of the breed
# this ruleset is for unwanted useragents... possibly email harvesters
RewriteCond %{HTTP_USER_AGENT} ^[A-Z]+$[NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.Browse\s[NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.Eval[NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.Surf [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*Harvest [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*HTTrack [NC,OR]
# RewriteCond %{HTTP_USER_AGENT} ^.*libwww-perl [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*LWP [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*prospector[NC,OR]
RewriteCond %{HTTP_USER_AGENT} AsiaNetBot [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ASSORT [NC,OR]
RewriteCond %{HTTP_USER_AGENT} attache [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ATHENS [NC,OR]
RewriteCond %{HTTP_USER_AGENT} autohttp [NC,OR]
RewriteCond %{HTTP_USER_AGENT} bew [NC,OR]
RewriteCond %{HTTP_USER_AGENT} BlackWidow [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Bot\ mailto:
[email protected] [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Bullseye [NC,OR]
RewriteCond %{HTTP_USER_AGENT} CherryPicker [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ChinaClaw[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Crescent [NC,OR]
RewriteCond %{HTTP_USER_AGENT} curl [NC,OR]
RewriteCond %{HTTP_USER_AGENT} devsoft's\ http\ component [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Deweb[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Digimarc [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Digger [NC,OR]
RewriteCond %{HTTP_USER_AGENT} digout4uagent[NC,OR]
RewriteCond %{HTTP_USER_AGENT} DIIbot [NC,OR]
RewriteCond %{HTTP_USER_AGENT} DISCo[NC,OR]
RewriteCond %{HTTP_USER_AGENT} dloader(NaverRobot) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Download\ Demon [NC,OR]
RewriteCond %{HTTP_USER_AGENT} eCatch [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ecollector [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Educate\ Search [NC,OR]
RewriteCond %{HTTP_USER_AGENT} EirGrabber [NC,OR]
RewriteCond %{HTTP_USER_AGENT} EmailCollector [NC,OR]
RewriteCond %{HTTP_USER_AGENT} EmailSiphon [NC,OR]
RewriteCond %{HTTP_USER_AGENT} EmailWolf[NC,OR]
RewriteCond %{HTTP_USER_AGENT} EO\ Browse [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Express\ WebPictures[NC,OR]
RewriteCond %{HTTP_USER_AGENT} ExtractorPro [NC,OR]
RewriteCond %{HTTP_USER_AGENT} EyeNetIE [NC,OR]
RewriteCond %{HTTP_USER_AGENT} fastlwspider [NC,OR]
RewriteCond %{HTTP_USER_AGENT} FEZhead[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Fetch[NC,OR]
RewriteCond %{HTTP_USER_AGENT} FlashGet [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Franklin\ Locator[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Full\ Web\ Bot [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Getleft [NC,OR]
RewriteCond %{HTTP_USER_AGENT} GetRight [NC,OR]
RewriteCond %{HTTP_USER_AGENT} GetURL [NC,OR]
RewriteCond %{HTTP_USER_AGENT} GetWebPage [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Go!Zilla [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Gozilla [NC,OR]
RewriteCond %{HTTP_USER_AGENT} go-ahead-got-it [NC,OR]
RewriteCond %{HTTP_USER_AGENT} GrabNet [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Grafula [NC,OR]
RewriteCond %{HTTP_USER_AGENT} HMView [NC,OR]
RewriteCond %{HTTP_USER_AGENT} HTML\ Works [NC,OR]
RewriteCond %{HTTP_USER_AGENT} HTTrack [NC,OR]
# RewriteCond %{HTTP_USER_AGENT} ia_archiver [NC,OR]
RewriteCond %{HTTP_USER_AGENT} IBM_Planetwide [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Image\ Stripper [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Image\ Sucker[NC,OR]
RewriteCond %{HTTP_USER_AGENT} IncyWincy[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Industry\ Program[NC,OR]
RewriteCond %{HTTP_USER_AGENT} InterGET [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Internet\ Explore\ 5\.x [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Internet\ Ninja [NC,OR]
RewriteCond %{HTTP_USER_AGENT} InternetSeer.com [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Irvine [NC,OR]
RewriteCond %{HTTP_USER_AGENT} JetCar [NC,OR]
RewriteCond %{HTTP_USER_AGENT} JOC\ Web\ Spider [NC,OR]
RewriteCond %{HTTP_USER_AGENT} KWebGet [NC,OR]
RewriteCond %{HTTP_USER_AGENT} larbin [NC,OR]
RewriteCond %{HTTP_USER_AGENT} leech[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mass\ Downloader [NC,OR]
RewriteCond %{HTTP_USER_AGENT} MCspider [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Microsoft\ URL [NC,OR]
RewriteCond %{HTTP_USER_AGENT} MIDown\ tool [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mirror [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Missauga\ Locator[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Missigua\ Locator[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mister\ PiX [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Monster [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mozilla.*NEWT[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mozilla\/3\.0\.\+Indy\ Library [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mozilla\/3.Mozilla\/2\.01 [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mozilla\/4\.0$ [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Mozzilla [NC,OR]
RewriteCond %{HTTP_USER_AGENT} MSIECrawler [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Navroad [NC,OR]
RewriteCond %{HTTP_USER_AGENT} NearSite [NC,OR]
RewriteCond %{HTTP_USER_AGENT} NetAnts [NC,OR]
RewriteCond %{HTTP_USER_AGENT} netattache [NC,OR]
RewriteCond %{HTTP_USER_AGENT} NetCarta [NC,OR]
RewriteCond %{HTTP_USER_AGENT} NetSpider[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Net\ Vampire [NC,OR]
RewriteCond %{HTTP_USER_AGENT} NetZIP [NC,OR]
RewriteCond %{HTTP_USER_AGENT} NICErsPRO[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Octopus [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Offline\ Explorer[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Offline\ Navigator [NC,OR]
RewriteCond %{HTTP_USER_AGENT} OpaL [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Openfind [NC,OR]
RewriteCond %{HTTP_USER_AGENT} OpenTextSiteCrawler [NC,OR]
RewriteCond %{HTTP_USER_AGENT} PackRat [NC,OR]
RewriteCond %{HTTP_USER_AGENT} PageGrabber [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Papa\ Foto [NC,OR]
RewriteCond %{HTTP_USER_AGENT} pavuk[NC,OR]
RewriteCond %{HTTP_USER_AGENT} pcBrowser[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Plucker [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Production\ Bot [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Program\ Shareware [NC,OR]
RewriteCond %{HTTP_USER_AGENT} PushSite [NC,OR]
RewriteCond %{HTTP_USER_AGENT} RealDownload [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ReGet[NC,OR]
RewriteCond %{HTTP_USER_AGENT} RepoMonkey [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Rover[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Rsync[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Siphon [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ScoutAbout [NC,OR]
RewriteCond %{HTTP_USER_AGENT} searchterms\.it [NC,OR]
RewriteCond %{HTTP_USER_AGENT} semanticdiscovery[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Shai [NC,OR]
RewriteCond %{HTTP_USER_AGENT} sitecheck[NC,OR]
RewriteCond %{HTTP_USER_AGENT} SiteSnagger [NC,OR]
RewriteCond %{HTTP_USER_AGENT} SmartDownload[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Spegla [NC,OR]
RewriteCond %{HTTP_USER_AGENT} SpiderBot[NC,OR]
RewriteCond %{HTTP_USER_AGENT} SuperBot [NC,OR]
RewriteCond %{HTTP_USER_AGENT} SuperHTTP[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Surfbot [NC,OR]
RewriteCond %{HTTP_USER_AGENT} SurfWalker [NC,OR]
RewriteCond %{HTTP_USER_AGENT} tAkeOut [NC,OR]
RewriteCond %{HTTP_USER_AGENT} tarspider[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Teleport\ Pro[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Telesoft [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Templeton[NC,OR]
RewriteCond %{HTTP_USER_AGENT} UtilMind [NC,OR]
RewriteCond %{HTTP_USER_AGENT} VoidEYE [NC,OR]
RewriteCond %{HTTP_USER_AGENT} w3mir[NC,OR]
RewriteCond %{HTTP_USER_AGENT} web.by.mail [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebBandit[NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebCopier[NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebCopy [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebEMailExtrac [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Web\ Image\ Collector[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Web\ Sucker [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebAuto [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebCopier[NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebFetch [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebMiner [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebReaper[NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebSauger[NC,OR]
RewriteCond %{HTTP_USER_AGENT} Website\ eXtractor [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Website\ Quester [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebSnake [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebStripper [NC,OR]
RewriteCond %{HTTP_USER_AGENT} webvac [NC,OR]
RewriteCond %{HTTP_USER_AGENT} webwalk [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebWhacker [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WebZIP [NC,OR]
# RewriteCond %{HTTP_USER_AGENT} wget [NC,OR]
RewriteCond %{HTTP_USER_AGENT} WhosTalking [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Widow[NC,OR]
RewriteCond %{HTTP_USER_AGENT} WUMPUS [NC,OR]
RewriteCond %{HTTP_USER_AGENT} www\.pl [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Xaldon\ WebSpider[NC,OR]
RewriteCond %{HTTP_USER_AGENT} XGET [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Yandex [NC,OR]
RewriteCond %{HTTP_USER_AGENT} Zeus.*Webster[NC]
#RewriteCond %{HTTP_USER_AGENT} test[NC]
RewriteCond %{REQUEST_URI}!^www\.yahoo\.com[NC]
RewriteRule .* www\.yahoo\.com