If you think you have it bad consider our poor European friends who must cope with the same movie being released by any number of studios in different countries under different titles! It's not illegal, nor intentionally devious. It's just who has distribution rights and what title they think will move it in their market.
Is there anything you can do? YES. Participate in this forum. We have any number of experts on various aspects of porn that can help you identify films and tell whether they are new or retreads.

