Watched a whole bunch of films labeled "noir". Eventually saw one that I thought was mis-labeled (though I don't remember now what it was). Spent some time pondering "What do all of these (except the mis-labeled one) have in common? Came to the conclusion that they all took place in a universe where justice would never be reliably enforced by The System, but could (possibly, provisionally, briefly) be imposed by the protagonist.

We discussed our conflicting definitions once before, but google is failing me...