(Not an important point, but it's kind of an unfortunate title. As someone who knew about the practice and its supposed origin in Naples, I thought the article was saying the practice does not (did not) ever actually exist in Naples. (In Naples, Gift of Coffee to Strangers Never Seen), i.e. despite the myth that it's common there.
It would be unambiguous if changed to "In Naples, Gift of Coffee to Unseen Strangers.")
It would be unambiguous if changed to "In Naples, Gift of Coffee to Unseen Strangers.")