Siri, the iPhone 4S's deadpan voice-activated assistant, is imperfect. She's stumped easily. Her command of English is only so so. In the U.K., she's a man. But is Siri a fraud?

A New York man represented by Robbins Geller is suing Apple for false advertising, alleging that the company's commercials convey a "misleading and deceptive message" about Siri's capabilities.

Frank...