What professional retailers do is purchase a certain number of units (or licenses) from the
manufacturer, say 50 units. They then sell 50. Then it is an effective incentive for the retailer
(with more sophisticated tools) to pursue said thieves. As far as "can't be done",
"impossible", it helps make a solution more probable. I have heard of links to the galleries here
being linked to other sites where some thief makes a profit off of them. Other sites prohibit hot linking.
To work for free,
whether you like to produce what you do or not is insane, from what I can see.