If the material is sold, that wouldn't be too hard now. 🙂 I don't know how it is in the states, but I know in Germany if you are identifiable on the clip, you always have the right to have it removed when it is published. Publishing alone is not totally legal, leave alone selling the material.
Yes, I suppose you are right, if the material is sold you can track it. But that is not the issue, I think. The issue is privacy in the era of the internet.
You can get the person. You can sue, and let say, you can also win. So his/her site goes down, if he/she is selling from a site. And you can get money for damages. All fine. But, after a material hit the internet, it will be reproduced from hundreds of times, and will be virtually immortal. It can be store in hundred of computers and resurrect in any time. So, if you feel embarrassed about the material, you have no solution.
Is not about publishing in the web, is about how do you recover all the copies, and since due to technology the cost of a perfect copy is zero, is enough to a single copy to survive to start all over again. Think about the Polaroid, and the nude shoot taken in parties, it was fun, and if you lost track of a picture….well how many people could see it before the paper just degraded? Now compare to a digital image, the last is virtually eternal.
So the damage to the privacy of a person is not done only by selling, but is simple done by showing some footage recorded without the permission of the person. Of course in the pre-internet, pre-you tube era, the scale of that damage was small to insignificant, it was only about the privacy of the famous. Selling only makes easier to catch the person.
Therefore, I think the real issue, is that privacy, as we used to conceive it, is no longer. You can be put on film almost in any place, for security reason in your city, in the elevator, etc. Remember the case of the executive that was caught by the camera making up with another from the same company, which was against the policy of the company in a security video and got fired. It was the street, a public place, in front of the company building, the security camera caught it.
The lesson is, from my point of view; if you are in public, assume you could be filmed, and end up in the web, it is not necessary at all a note or ad telling you that, today to know that is basic survival instinct. If you go to a Renfair party, then you know you could be filmed, and it could be ending up as fetish material for sexual gratification. Period.
A paedophile could said…Great!!!, so I can too go to children parties and meetings and film them, and distribute it on the web, it happens in public, so it is the same…. Well, no, Paedophilia is a crime is worth to invest the resources to track you down and put you away. Privacy on the other hand is not. Your best protection for your privacy is to remember, cameras are so cheap and so easy to hide, and images so cheap to reproduce then assume in public you could be caught on film.
Privacy is not what it used to be, but as a consolation, it could happen to all of us, somebody can be very happy of Renfair tickling material and not caring about how it was obtained, but in turn he/she could be caught in a non tickling situation that for any reason he/she would not like to be shown in the web, but since it happen in a public place, deal with it.
This lost of privacy is not all bad, it helps to prevent crimes, police abuse and many other good things too. Also, today some people could find a bit paranoid that cameras are everywhere, but maybe in 20 years time is will be a fact of life like any other.