What is a Hijacked IP Block and why would I want to block it?
From CompleteWhois: Hijacked IP space are IP blocks that are being used without permission by organizations that have no relation to original organization (or its legal successor) that received the IP block. In essence it’s stealing of somebody else’s IP resources. These ranges are being used illegally and are most likely being used for illegal activities. They should not be being used and should therefore be blocked.