Heres a piece of both comic-book trivia and IP trivia that I didnt previously know: the DC character Brainiac humanoid computer and frequent Superman antagonist originally was just some green alien guy and (despite his computer-sounding name) not a computer at all. But when the prior inventor of a toy computer likewise named Brainiac raised legal objections to the use of the name, DC and the inventor reached an imaginative win-win compromise: DC made their Brainiac more (rather than less) like the original they were accused of infringing i.e., made him a computer thus turning the character into an ad for the toy and so obviating the toymakers objections. The issue of Superman that inaugurated this compromise even parodied the rights dispute on its cover by having Brainiac and Lex Luthor debating which of them has a better right to kill Superman. Details here.
I wonder if this could translate into a common voluntaryist solution to conflicts in a world free of state backed IP?