Begin Two cents;
htaccess referrer protection is easy to implement and works great. Google for it or consult the photopost site.
But the support issues will kill you. Many adults saw ZoneAlarm et. al. selling them "privacy and security and safety" so they snapped it up. Now their browsers are not sending referrers in the headers, and the adults haven't got a clue how to configure their privacy to make an exception for your site.
Or, scan your weblogs every once in a while and start using htaccess to block the unknowns. Or... this is a subject that thrives in adult webmaster forums.
Don't let it bog down gallery development. Keep the coding at vb
strength: solid php code is the best defense.
Never show direct urls. I haven't seen the gallery do that yet, but I'm still just getting wet. If a body is going to gig through the html to pull out the url, you have a genuine and determined thief on your hands. It's outside the scope of this software.
End two cents;