Say you want to use data to train a machine learning model to solve some task. What if the data is published under a Creative Commons license with the Non-Commercial module? Clearly, you cannot put the data to direct commercial use, like linking it with other data and selling it.
However, can you use the model in a commercial setting, if it was derived from those CC-NC data?
I found only one remotely relevant interpretation in the CC FAQs:
Commercial purposes: If you are conducting text and data mining for commercial purposes, you should not mine NC-licensed databases or other material.
However a statistical model derived in a machine learning process from a data set is not exactly data mining, IMHO. Also, the should is very vague.