Dark data is the information organizations collect but never use. It often sits...

https://blast-wiki.win/index.php/How_Do_I_Build_a_Business_Case_for_Dark_Data_Cleanup%3F

Dark data is the information organizations collect but never use. It often sits inactive, with 60-80% of data going untouched. This hidden data takes up storage, drives up costs, and can hide security risks