A German operator of a Tor server used to anonymously route traffic over the net said he was arrested in a midnight raid on his residence that stemmed from an investigation into bomb threats said to have passed through an internet protocol address under his control.

Alexander Janssen said he had just returned from a night of drinking when someone knocked "very hard" on his door. Police then entered his Dusseldorf apartment, cuffed him and said he was suspected of posting bomb threats in a German forum related to law enforcement. He told police he operated a Tor server, which typically funneled 40 GB of data per day, but the officers proceeded to search his attic, office, car - even through the undergarments of his terrified wife. He was later taken to a police station and interrogated.

Janssen says he was ultimately released by a federal German official who acknowledged police had made a mistake. But the experience has weighed so heavily on Janssen, who says he works as an engineer for a big IT company, that he has decided to abandon his Tor activities.

"I can't do this any more, my wife and I were scared to death," Janssen wrote in a detailed blog entry. I’m at the end of my civil courage. I’ll keep engaged in the Tor-project but I won’t run a server any more. Sorry."

A blog post by Chris Soghoian, a graduate student in the school of Informatics at Indiana University, points out this isn't the first time anonymity technology has been targeted by law enforcement. Last year, German authorities seized 10 Tor servers in an investigation related to child pornography. And in 2003, he says a German court ordered developers of a separate anonymity system known as Jap to build in a back door that authorities could access when conducting investigations related to national security.

"This event does raise some interesting legal questions," Soghoian writes. "If 40GB of other people's Internet traffic flows through your own home network, can authorities, be they the RIAA or FBI reasonably link anything that has been tracked to your computer's IP address to you?"

But while Tor can be certainly be used to cover up crimes, Janssen's account of the experience serves as a potent reminder that what law enforcement officials don't know about the internet can have profound consequences. Not only did it lead to officers raiding the home of an innocent individual, it is also be seen as a setback, however small, for grass-roots projects such as Tor, that aim to shield individuals from prying eyes. ®

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