This dangerous topic, unknown includes all those secret facts, which as an individual or collectively we, do not currently know. The search to discover what is unknown is the search for truth. This ignorance stems from a lack of knowledge, information, or data or from inaccurate, misunderstood or not recognised findings.
For some topics even though it is wanted, there is no information available while some information needs verification to be trusted. If something is vague, fuzzy, questionable or otherwise unknown it may create discussion and debate.