At this very moment, the largest cyber attack ever declared is emanating from a decommissioned, nuclear-war proof NATO bunker with five foot-thick concrete walls and a reputation for harboring spammers and cybercriminals. It’s all part of a dustup between CyberBunker—so named for the building just outside Kloetinge, in the Netherlands, that houses its servers—and the international non-profit Spamhaus.
CyberBunker does what its name suggests: It’s a safe place full of computers, which host websites and data stores for various companies. Spamhaus, meanwhile, tracks internet addresses that are sources of email spam, and adds their addresses to a blacklist. Companies that use this blacklist—which include pretty much every email provider and most internet service providers on the planet—automatically block those addresses.