New submitter krakman writes "The Washington Post has an interesting story about how the FBI can investigate and collect details from computers over the net, without knowing anything about the computer location. Here's an example of the FBI's network investigative techniques: '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. ... The FBI’s elite hacker team designed a piece of malicious software that was to be delivered secretly when Mo signed on to his Yahoo e-mail account, from any computer anywhere in the world, according to the documents. The goal of the software was to gather a range of information — Web sites he had visited and indicators of the location of the computer — that would allow investigators to find Mo and tie him to the bomb threats. ... Even though investigators suspected that Mo was in Iran, the uncertainty around his identity and location complicated the case. Had he turned out to be a U.S. citizen or a foreigner living within the country, a search conducted without a warrant could have jeopardized his prosecution. ...But, [a court document] said, Mo’s computer did send a request for information to the FBI computer, revealing two new IP addresses in the process. Both suggested that, as of last December, Mo was still in Tehran.'"