My .htaccess to stop referral spam

I ganked this from someplace on the net, can't remember where or I'd give credit. It successfully stops most of the referral spam, and when someone sneaks by I can add them to the list if need be. Obvously you can edit it to be smaller if you like and still catch most of them. Here you go:

# Block Referrer Spam

# Drugs / Herbal

RewriteCond %{HTTP_REFERER} (sleep-?deprivation) [NC,OR]
RewriteCond %{HTTP_REFERER} (sleep-?disorders) [NC,OR]
RewriteCond %{HTTP_REFERER} (insomnia) [NC,OR]
RewriteCond %{HTTP_REFERER} (phentermine) [NC,OR]
RewriteCond %{HTTP_REFERER} (phentemine) [NC,OR]
RewriteCond %{HTTP_REFERER} (vicodin) [NC,OR]
RewriteCond %{HTTP_REFERER} (hydrocodone) [NC,OR]
RewriteCond %{HTTP_REFERER} (levitra) [NC,OR]
RewriteCond %{HTTP_REFERER} (hgh-) [NC,OR]
RewriteCond %{HTTP_REFERER} (-hgh) [NC,OR]
RewriteCond %{HTTP_REFERER} (ultram-) [NC,OR]
RewriteCond %{HTTP_REFERER} (-ultram) [NC,OR]
RewriteCond %{HTTP_REFERER} (cialis) [NC,OR]
RewriteCond %{HTTP_REFERER} (soma-) [NC,OR]
RewriteCond %{HTTP_REFERER} (-soma) [NC,OR]
RewriteCond %{HTTP_REFERER} (diazepam) [NC,OR] 
RewriteCond %{HTTP_REFERER} (gabapentin) [NC,OR]
RewriteCond %{HTTP_REFERER} (celebrex) [NC,OR]
RewriteCond %{HTTP_REFERER} (viagra) [NC,OR]
RewriteCond %{HTTP_REFERER} (fioricet) [NC,OR]
RewriteCond %{HTTP_REFERER} (ambien) [NC,OR]
RewriteCond %{HTTP_REFERER} (valium) [NC,OR]
RewriteCond %{HTTP_REFERER} (zoloft) [NC,OR]
RewriteCond %{HTTP_REFERER} (finasteride) [NC,OR]
RewriteCond %{HTTP_REFERER} (lamisil) [NC,OR]
RewriteCond %{HTTP_REFERER} (meridia) [NC,OR]
RewriteCond %{HTTP_REFERER} (allegra) [NC,OR]
RewriteCond %{HTTP_REFERER} (diflucan) [NC,OR]
RewriteCond %{HTTP_REFERER} (zovirax) [NC,OR]
RewriteCond %{HTTP_REFERER} (valtrex) [NC,OR]
RewriteCond %{HTTP_REFERER} (lipitor) [NC,OR]
RewriteCond %{HTTP_REFERER} (proscar) [NC,OR]
RewriteCond %{HTTP_REFERER} (acyclovir) [NC,OR]
RewriteCond %{HTTP_REFERER} (sildenafil) [NC,OR]
RewriteCond %{HTTP_REFERER} (tadalafil) [NC,OR]
RewriteCond %{HTTP_REFERER} (xenical) [NC,OR]
RewriteCond %{HTTP_REFERER} (melatonin) [NC,OR]
RewriteCond %{HTTP_REFERER} (xanax) [NC,OR]
RewriteCond %{HTTP_REFERER} (herbal) [NC,OR]
RewriteCond %{HTTP_REFERER} (drugs) [NC,OR]
RewriteCond %{HTTP_REFERER} (lortab) [NC,OR]
RewriteCond %{HTTP_REFERER} (adipex) [NC,OR]
RewriteCond %{HTTP_REFERER} (propecia) [NC,OR]
RewriteCond %{HTTP_REFERER} (carisoprodol) [NC,OR]
RewriteCond %{HTTP_REFERER} (tramadol) [NC]
RewriteRule .* - [F]

# Porn

RewriteCond %{HTTP_REFERER} (porno) [NC,OR]
RewriteCond %{HTTP_REFERER} (shemale) [NC,OR]
RewriteCond %{HTTP_REFERER} (gangbang) [NC,OR]
RewriteCond %{HTTP_REFERER} (-cock) [NC,OR]
RewriteCond %{HTTP_REFERER} (-anal) [NC,OR]
RewriteCond %{HTTP_REFERER} (-orgy) [NC,OR]
RewriteCond %{HTTP_REFERER} (cock-) [NC,OR]
RewriteCond %{HTTP_REFERER} (anal-) [NC,OR]
RewriteCond %{HTTP_REFERER} (orgy-) [NC,OR]
RewriteCond %{HTTP_REFERER} (singles-?christian) [NC,OR]
RewriteCond %{HTTP_REFERER} (dating-?christian) [NC,OR]
RewriteCond %{HTTP_REFERER} (cumeating) [NC,OR]
RewriteCond %{HTTP_REFERER} (cream-?pies) [NC,OR]
RewriteCond %{HTTP_REFERER} (cumsucking) [NC,OR]
RewriteCond %{HTTP_REFERER} (cumswapping) [NC,OR]
RewriteCond %{HTTP_REFERER} (cumfilled) [NC,OR]
RewriteCond %{HTTP_REFERER} (cumdripping) [NC,OR]
RewriteCond %{HTTP_REFERER} (krankenversicherung) [NC,OR]
RewriteCond %{HTTP_REFERER} (cumpussy) [NC,OR]
RewriteCond %{HTTP_REFERER} (suckingcum) [NC,OR]
RewriteCond %{HTTP_REFERER} (drippingcum) [NC,OR]
RewriteCond %{HTTP_REFERER} (pussycum) [NC,OR]
RewriteCond %{HTTP_REFERER} (swappingcum) [NC,OR]
RewriteCond %{HTTP_REFERER} (eatingcum) [NC,OR]
RewriteCond %{HTTP_REFERER} (cum-) [NC,OR]
RewriteCond %{HTTP_REFERER} (-cum) [NC,OR]
RewriteCond %{HTTP_REFERER} (sperm) [NC,OR]
RewriteCond %{HTTP_REFERER} (christian-?dating) [NC,OR]
RewriteCond %{HTTP_REFERER} (jewish-?singles) [NC,OR]
RewriteCond %{HTTP_REFERER} (sex-?meetings) [NC,OR]
RewriteCond %{HTTP_REFERER} (swinging) [NC,OR]
RewriteCond %{HTTP_REFERER} (swingers) [NC,OR]
RewriteCond %{HTTP_REFERER} (personals) [NC,OR]
RewriteCond %{HTTP_REFERER} (sleeping) [NC,OR]
RewriteCond %{HTTP_REFERER} (libido) [NC,OR]
RewriteCond %{HTTP_REFERER} (grannies) [NC,OR]
RewriteCond %{HTTP_REFERER} (mature) [NC,OR]
RewriteCond %{HTTP_REFERER} (enhancement) [NC,OR]
RewriteCond %{HTTP_REFERER} (sexual) [NC,OR]
RewriteCond %{HTTP_REFERER} (gay-?teen) [NC,OR]
RewriteCond %{HTTP_REFERER} (teen-?chat) [NC,OR]
RewriteCond %{HTTP_REFERER} (gay-?chat) [NC,OR]
RewriteCond %{HTTP_REFERER} (adult-?finder) [NC,OR]
RewriteCond %{HTTP_REFERER} (adult-?friend) [NC,OR]
RewriteCond %{HTTP_REFERER} (friend-?finder) [NC,OR]
RewriteCond %{HTTP_REFERER} (friend-?adult) [NC,OR]
RewriteCond %{HTTP_REFERER} (finder-?adult) [NC,OR]
RewriteCond %{HTTP_REFERER} (finder-?friend) [NC,OR]
RewriteCond %{HTTP_REFERER} (discrete-?encounters) [NC,OR]
RewriteCond %{HTTP_REFERER} (cheating-?wives) [NC,OR]
RewriteCond %{HTTP_REFERER} (housewives) [NC,OR]
RewriteCond %{HTTP_REFERER} (\-sex\.) [NC,OR]
RewriteCond %{HTTP_REFERER} (xxx) [NC,OR]
RewriteCond %{HTTP_REFERER} (snowballing) [NC] 
RewriteRule .* - [F]

# Weight

RewriteCond %{HTTP_REFERER} (fat-) [NC,OR] 
RewriteCond %{HTTP_REFERER} (-fat) [NC,OR] 
RewriteCond %{HTTP_REFERER} (diet) [NC,OR]
RewriteCond %{HTTP_REFERER} (pills) [NC,OR]
RewriteCond %{HTTP_REFERER} (weight) [NC,OR]
RewriteCond %{HTTP_REFERER} (supplement) [NC] 
RewriteRule .* - [F] 

# Gambling

RewriteCond %{HTTP_REFERER} (texas-?hold-?em) [NC,OR]
RewriteCond %{HTTP_REFERER} (poker) [NC,OR]
RewriteCond %{HTTP_REFERER} (casino) [NC,OR]
RewriteCond %{HTTP_REFERER} (blackjack) [NC] 
RewriteRule .* - [F]

# Loans / Finance

RewriteCond %{HTTP_REFERER} (mortgage) [NC,OR]
RewriteCond %{HTTP_REFERER} (consolidation) [NC,OR]
RewriteCond %{HTTP_REFERER} (refinancing) [NC,OR]
RewriteCond %{HTTP_REFERER} (cash-?advance) [NC,OR]
RewriteCond %{HTTP_REFERER} (cash-?money) [NC,OR]
RewriteCond %{HTTP_REFERER} (pay-?day) [NC] 
RewriteRule .* - [F]

# User Agents

RewriteCond %{HTTP_USER_AGENT} (Program\ Shareware|Fetch\ API\ Request) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (Microsoft\ URL\ Control) [NC]
RewriteRule .* - [F]

# Misc / Specific Sites

RewriteCond %{HTTP_REFERER} (netwasgroup\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (nic4u\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (wear4u\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (foxmediasolutions\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (liveplanets\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (aeterna-tech\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (continentaltirebowl\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (chemsymphony\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (infolibria\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (globaleducationeurope\.net) [NC,OR]
RewriteCond %{HTTP_REFERER} (soma\.125mb\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (mitglied\.lycos\.de) [NC,OR]
RewriteCond %{HTTP_REFERER} (foxmediasolutions\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (jroundup\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (feathersandfurvanlines\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (conecrusher\.org) [NC,OR]
RewriteCond %{HTTP_REFERER} (sbj-broadcasting\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (edthompson\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (codychesnutt\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (artsmallforsenate\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (axionfootwear\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (protzonbeer\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (candiria\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (bigsitecity\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (coresat\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (istarthere\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (amateurvoetbal\.net) [NC,OR]
RewriteCond %{HTTP_REFERER} (alleghanyeda\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (xadulthosting\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (datashaping\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (zick\.biz) [NC,OR]
RewriteCond %{HTTP_REFERER} (newprinceton\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (dvdsqueeze\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (xopy\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (webdevboard\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (devaddict\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (eaton-inc\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (whiteguysgroup\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (guestbookz\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (webdevsquare\.com) [NC,OR]
RewriteCond %{HTTP_REFERER} (indfx\.net) [NC,OR]
RewriteCond %{HTTP_REFERER} (snap\.to) [NC,OR]
RewriteCond %{HTTP_REFERER} (2y\.net) [NC,OR]
RewriteCond %{HTTP_REFERER} (astromagia\.info) [NC,OR]
RewriteCond %{HTTP_REFERER} (free-?sms) [NC] 
RewriteRule .* - [F]

Code (markup):

 

Nice Does that many rewrites create additional load though?

 

Didn't notice a difference at all, and this was on a VPS with 4 forums and 20 sites getting 15k visits / day and I'm also using alot of mod-rewrite for the url's. But, if it's a concern, you can remove probably 3/4 of the RewriteCond leaving just the really common stuff.

 

Thanks mdvaldosta

Don't think this make difference on server load as my current .htaccess is 36k and the performance is the same as when it was just 1k

 

That would really keep me going, i really hate spams