mod_rewrite: Forbid Unsavory Visitors

I have a another blog that mentions random words like "daughter","school", "dirty", "bad", "dog", "herself", "year", "nasty" and "old." Until I started revewing my HTTP referers, It never even occured to me that nasty perverts could end up on my site while looking for websites that contain the words "11 year old dirty asian daughter in school with dog." Even though my blog wouldn't come close to providing what they were looking for, I still didn't want these unwelcomed visitors seeing it so I enabed mod_rewrite on my Apache install and wrote the following script to detect people coming from search engines who are looking for unfavorable stuff.

RewriteEngine On RewriteBase / RewriteCond %{HTTP_REFERER} !https://(www\.)?*$ [NC] RewriteCond %{HTTP_REFERER} !.*my*web*site.*$ [NC] RewriteCond %{HTTP_REFERER} ^.*(google|yahoo|msn|search).*$ [NC] RewriteCond %{HTTP_REFERER} ^.*(daughter|herself||asian|dog|little|school|girls.*nasty|taste.*self|year|girl.*old).*$ [NC] RewriteRule .* - [F]

Here is what the script performs, step by step. 1. If the module mod_rewrite is enabled do the following 2. Turn Rewrite Engine On 3. Apply it to the entire site 4. If referer is not or a variation of my site's name 5. AND they come from a search engine 6. AND the URL includes the following combination of words/phrases: nasty AND (daughter or herself or asian or dog or little or school or girls) or taste AND self or old AND (year or girl) 7. Give them a 403 Forbidden 8. End of script

I placed this script in the root of my website and it worked perfectly. Of course, the person can easily get around this but I'd say over 99% just think the site is outdated/broken and won't even attempt it.