Denial-of-service attacks are used by hackers to flood Web servers with traffic, slowing it down or, worse, crashing it. That same idea is now being used translated to telephones. Telephony denial-of-service attackers are spammers who call first responders on administrative, nonemergency lines, flooding them with phony calls about nonexistent debt. While 911 lines have yet to be hit, they are the most vulnerable target, according to the Department of Homeland Security.
