I would negotiate a different contract, depending on how my work would be used. Being paid is only half the story. Like software licenses: you can use this for free if you release your own code as GPL, but we’ll come to a different agreement if you want to use it differently. Different terms for different use cases.
I wouldn’t be surprised to see that change at some point. There was no reason to exclude impossible uses in the contracts, but as those uses become possible, people will probably want to have provisions that they share in the fruits of their own labor.
Since a lot of these new uses seem to be ‘fair use,’ it might require changes to IP law.
