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Cops' Warrantless Cell Phone Tracking Now Better Than GPS
Sparrowvsrevolution writes "On Thursday, the House Judiciary Committee held a hearing to discuss a proposed bill to limit location tracking of electronic devices without a warrant — what it's calling the Geolocational Privacy and Surveillance Act, or the GPS Act. Ahead of that hearing, University of Pennsylvania computer science professor Matt Blaze submitted written testimony (PDF) telling Congress that phone carriers, as well as the law enforcement agencies with which they share data, can now use phones' proximity to cell towers and other sources of cellular data to track their location as precisely or even more precisely than they can with global positioning satellites. Thanks to the growing density of cell towers and the proliferation of devices like picocells and femtocells that transmit cell signals indoors, even GPS-less phones can be tracked with a high degree of precision and can offer data that GPS can't, like the location of someone inside a building or what floor they're on. With the GPS Act, Congress is considering expanding the ban on warrantless tracking of cars with GPS devices that the Supreme Court decided on in January. Blaze's testimony suggests they need to include non-GPS tracking of cell phones in that ban, a measure law enforcement agencies are strongly resisting."
"Except that surveillance, simply having an approximate idea where you are, is not now, and never was a search." Incorrect, if you read the decision on GPS, the problem was not with knowing where people were, either very specifically, or generally, but with the amount of time that knowledge was available. The previous decision makes it quite clear that even a general knowledge, over anything other than an incidental period of time, is a violation.
Presumably they have more information than just which cell tower you are most strongly connected to. Cell towers generally have directional antennas, and have more of them in denser areas, so they will have a pretty good idea what direction from the tower you are in.
That is exactly right. Each cell tower has 2 - 6 cells, the borders of which are usually measured somewhat approximately by the operator. So they know which cell you are in, which tells them the rough area around the cell tower that you are in.
They also have the ability to measure round-trip time for signals sent to your phone, giving a rough estimate of the distance from the tower to you, inside your cell (this actually becomes less accurate when signal reflection is an issue).
Finally, the cell phone constantly measures _all_ cells it can find. Not just the ones belonging to your operator, but other operators as well, including (if the phone is capable) 2G, 3G and 4G cells. All this is reported back to the radio network controller to assist with handover decisions between cells, so your operator (and thus anyone else with enough authority) can access this information.
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Because we aren't a direct democracy. Majority opinion doesn't always become law, and it definitely doesn't happen immediately. That's by design. But it still lies with the people to select the government. If our government representatives aren't doing what we want, then we have the power to select new representatives. If they're not doing what we want but we're re-electing them anyway, then that's our fault. No amount of money and corporate friends can buy a place in Congress. Instead, all that cash buys votes, but it's our fault for putting our votes up for sale.
A beauracracy the size of the US government will always have corruption in it, but it still always comes back to us when we don't remove those responsible.