User-agent: *

RewriteCond %{HTTP_REFERER} !^https://(www\.)?poral.eu/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^https://(www\.)?facebook.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^https://(www\.)?google.com/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^https://(www\.)?google.pl/.*$ [NC]
RewriteCond %{HTTP_REFERER} !^https://(www\.)?poral.net/.*$ [NC]
RewriteRule \.(jpg|png)$ https://ericsson.poral.net/pliki/poraleu_logo_jpg.png [R,L]