Regardless, this is sort of discrimination against certain EU nationals is illegal within the EU, and it further appears to be systemic (my partner was told: "all Italian passport holders must present alternative ID") and possibly an illegal policy of Norwegian Airlines.

Besides complaining to Norwegian Airlines, any other avenues we should try? I have thought of writing to the Italian embassy, and the EU's SOLVIT, but before we try those, are there other regulators or institutions that we should consider notifying?