Cell Phone Premonitions
Aug 7, 2007
The Freakonomics Blog mentioned a story about mobile phone providers knowing that something was happening near the I-35 bridge in Minneapolis due to hugely increased call volumes. Later in the article there is also a mention of T-Mobile tracking the change in commuting patterns by the movement of cell phones.
Cell phone activity, just like any side-channel attack, can be exploited to learn a lot about a population. There are certainly legal and privacy implications to such data being made public, but it would be amazing to look at from a research point of view.