Hmm, interesting thread ... but don't lose your health over it.

As an engineer doing many patentable things ... I don't bother since I'm small and don't have a million$ legal fund.  Quoting copyright laws means nothing if you are not willing to HIRE a lawyer in the country where the OFFENDER lives.  Plus even then, cases where small companies go into debt & struggle for years to sue over patent infringement usually end with the same story: The offender just moves across town and starts up again with a new name; hello square one.

DAZ will view this the same way as the credit-card companies handle fraud ... we lose $X per quarter; spending 10 times X to save X doesn't make sense. 

Any of these people who give your work away or sell it, if you spend huge emotional effort to stop them ... they will be doing it again tomorrow as someone else with a new name.  So be diliggent, plug up the holes you can but don't take it personally or let your health suffer.