Dark data is the information collected but never used, often making up 55% of...

https://wool-wiki.win/index.php/Dark_Data_in_Object_Storage_%E2%80%93_Why_Do_Buckets_Get_Out_of_Control%3F

Dark data is the information collected but never used, often making up 55% of stored data. It poses real risks like ransomware exposure because it's unmonitored and can hide vulnerabilities