mumble attack
 n.— «Online cell-phone record vendors placed hundreds of thousands of calls to Verizon customer service requesting customer account information while posing as Verizon employees from the company’s “special needs group,” a nonexistent department. The caller would claim to be making the request on behalf of a voice-impaired customer who was unable to request the records himself. If the service representative asked to speak with the customer directly, the caller would impersonate a voice-impaired customer, using a mechanical device to distort his voice and make it impossible for the service representative to understand him—a variant of a widely used social-engineering technique known as the “mumble attack.”» —“Devious Tactic Snags Phone Data” by Kim Zetter Wired News Jan. 17, 2006. (source: Double-Tongued Dictionary)

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