"The man who called himself “Mo” had dark hair, a foreign accent and — if the pictures he e-mailed to federal investigators could be believed — an Iranian military uniform. When he made a series of threats to detonate bombs at universities and airports across a wide swath of the United States last year, police had to scramble every time.
Mo remained elusive for months, communicating via e-mail, video chat and an Internet-based phone service without revealing his true identity or location, court documents show. So with no house to search or telephone to tap, investigators turned to a new kind of surveillance tool delivered over the Internet."
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