Specifically, I'm referring to service like Pixsy (just an example). What they do is, send (mostly automated) demand letters (threatening litigation) to copyright infringers, once they have detected any image being infringed by their image tracker. This process is requested by copyright's owner (along the rights to do it in their ToS). If the infringer pays them up, they take 50% and share 50% with the copyright's owner.
So, my question or rather discussion is about, what sort of legal risks or requirements would be involved doing this sort of procedure? Can anyone commercially send demand letters and take profit from them (just by structuring up their Terms of Service regarding the rights?) Or are there specific requirements that must be fulfilled before one sends such demand letter on behalf on the copyright's owner. Could there be any sort of risk involded?
This is assuming that copyright's owner has actually requested them to send the letter and it's not a fraud.
Also what would be a way for identifying that the letter's sender is legitimately representing the copyright's owner? In case where the sender is not willing to provide any communication with the copyright's owner?
Thanks for your time! I'm not asking anyone to give me legal advise. This is a general discussion regarding legal rights. So give me your opinions!