Kashmir Hill has a fascinating story
today on what can go wrong when you solely rely on IP address in a crime investigation -- also highlighting how often police resort to IP addresses. In the story she follows a crime investigation that led police to raid a couple's house at 6am in the morning, because their IP address had been associated with the publication of child porn on notorious 4chan porn. The problem was, Hill writes: the couple -- David Robinson and Jan Bultmann -- weren't the ones who had uploaded the child porn
. All they did was voluntarily use one of their old laptops as a Tor exit relay, a software used by activists, dissidents, privacy enthusiasts as well as criminals, so that people who want to stay anonymous when surfing the web could do so. Hill writes: Robinson and Bultmann had [...] specifically operated the riskiest node in the chain: the exit relay which provides the IP address ultimately associated with a user's activity. In this case, someone used Tor to make the porn post, and his or her traffic had been routed through the computer in Robinson and Bultmann's house. The couple wasn't pleased to have helped someone post child porn to the internet, but that's the thing about privacy-protective tools: They're going to be used for good and bad purposes, and to support one, you might have to support the other.
Robinson added that he was a little let down because police didn't bother to look at the public list
which details the IP addresses associated with Tor exit relays. Hill adds: The police asked Robinson to unlock one MacBook Air, and then seemed satisfied these weren't the criminals they were looking for and left. But months later, the case remains open with Robinson and Bultmann's names on police documents linking them to child pornography. "I haven't run an exit relay since. The police told me they'd be back if it happened again," Robinson said; he's still running a Tor node, just not the end point anymore. "I have to take the threat seriously because I don't want my wife or I to wake up with guns in our faces."
Technologist Seth Schoen, and EFF Executive Director Cindy Cohn in a white paper
aimed at courts and cops. "For many reasons, connecting an individual to a crime linked to an IP address, without any additional investigation, is irresponsible and threatens the civil liberties of innocent people."