AuthUserFile /dev/null
AuthGroupFile /dev/null
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^
http://www.site1.nl [NC]
RewriteCond %{HTTP_REFERER} !^
http://site1.nl [NC]
RewriteCond %{HTTP_REFERER} !^
http://www.site2.nl/ [NC]
RewriteCond %{HTTP_REFERER} !^
http://site2.nl/ [NC]
RewriteRule /*
http://backtowhereyoucamfrom.nl [R,L]
This should work
edit: Let m eknow if it did work :-)