According to Brian Dunning, researchers should be concerned about the fact that there are no documented "confirmed observations" of earthquake lights. It is a red flag that there is no consistency of what they are, when they happen, and where they happen. It is likely that there "is not one, known, proven phenomenon". However, a significant amount of video footage has surfaced since the advent of sites like YouTube that claim to represent this—one example being the 2017 Mexico earthquake—although no consistent explanation has been agreed upon. There is also a "staggering volume of literature... hardly any of these papers agree on anything... I'm forced to wonder how many of these eager researchers are familiar with Hyman's Categorical Imperative: 'Do not try to explain something until you are sure there is something to be explained'". Dunning's final conclusion is that until there is "pending decent evidence" be skeptical of claims of earthquake lights.