Today the ACLU sued the Justice Department to force it to reveal its policies for tracking the location of cell phones. As anyone who watches Law & Order: SVU knows, all cell phones double as tracking devices.They send cell phone networks information that provides a pretty accurate idea of where they are physically located. This means that if you go for a walk around town with a cell phone in your pocket, it is possible for your cell phone provider to trace your route.
At least today, your cell phone provider does not have a business reason to keep such close track of you. But the government has plenty of reasons to want to do so. The question is under what circumstances the government is going to be able to access such information.
The ACLU’s position is that people have a reasonable expectation that their movements will not be tracked, especially when they are in private places such as homes, and that the government should have to get a warrant from a court to obtain cell phone location information. The government disagrees. News reports and court decisions (PDF) indicate that the Justice Department has been asking courts to authorize it to get this information without producing evidence sufficient to get a warrant, and sometimes without any court involvement at all.
Sometimes the government wins, sometimes it does not. But the few cases that garner press attention or result in court opinions are likely to be a small subset of the number of times the government engages in such tracking.
The purpose of the lawsuit the ACLU filed today is to get the Justice Department to reveal its policies for when it tracks the location of people’s cell phones. The public has the right to know how widespread such monitoring is, so that they can fairly evaluate the privacy risks of carrying a cell phone.