Assuming it's TS/SCI: it's a highly classified and compartmentalized type of US classified material. Generally if you hold a clearance you don't want to access

Assuming it's TS/SCI: it's a highly classified and compartmentalized type of US classified material. Generally if you hold a clearance you don't want to access those links on a work computer, because DOD/DOI still consider it "contaminating" and unclassified system with classified material even if the material has been leaked to the public.