# Block Googlebot and Adsbot
#User-agent: Googlebot
#User-agent: AdsBot-Google
User-Agent: *
Disallow: /
In httpd.conf:

RewriteCond %{HTTP_USER_AGENT} "Google-Read-Aloud"
RewriteRule ^(.*)$ "-" [F]

RewriteCond %{HTTP_USER_AGENT} "Amazonbot"
RewriteRule ^(.*)$ "-" [F]

RewriteCond %{HTTP_USER_AGENT} "Facebot Twitterbot"
RewriteRule ^(.*)$ "-" [F]

RewriteCond %{HTTP_USER_AGENT} "mj12bot.com"
RewriteRule ^(.*)$ "-" [F]