Block proxy

RewriteEngine on
RewriteCond %{HTTP:XROXY_CONNECTION}    !^$ [OR]
RewriteCond %{HTTP:X-FORWARDED-FOR}     !^$ [OR]
RewriteCond %{HTTP:FORWARDED-FOR}       !^$ [OR]
RewriteCond %{HTTP:X-FORWARDED}         !^$ [OR]
RewriteCond %{HTTP:VIA}                 !^$ [OR]
RewriteCond %{HTTP:FORWARDED}           !^$ [OR]
RewriteCond %{HTTP:USERAGENT_VIA}       !^$ [OR]
RewriteCond %{HTTP:X_FORWARDED_FOR}     !^$ [OR]
RewriteCond %{HTTP:PROXY_CONNECTION}    !^$ [OR]
RewriteCond %{HTTP:XPROXY_CONNECTION}   !^$ [OR]
RewriteCond %{HTTP:HTTP_PC_REMOTE_ADDR} !^$ [OR]
RewriteCond %{HTTP:HTTP_CLIENT_IP}      !^$
RewriteRule ^(.*)$ - [F]