IANAL but my sense is that it will be a number of years before we really know what works with regards to this kind of licensing of DNN/ML training data sets. It

IANAL but my sense is that it will be a number of years before we really know what works with regards to this kind of licensing of DNN/ML training data sets. It's almost certainly going to be decided on the basis of what's called "case law", which really just means "a bunch of random judges who don't know anything about ML made decisions on a bunch of random lawsuits that probably were not good samples to pick and which were probably taken to court by pairs of parties with wildly different abilities to pay lawyers and now we are stuck with those decisions as precedent for future cases." If that sounds like a crappy legal footing for the next 20 years of software development, yeah, it is. It's also why Mitch Kapor and a few others founded and funded the EFF to try to encourage better case law decisions around the early days of electronic privacy law. We definitely need an EFF like effort around ML/DNN/etc., but I'm not holding my breath. I wish I had a better answer, I'm mostly hoping someone else here does.