Security Ledger, 3/26/13:
(A) Shows the trace of an anonymized mobile phone user during a day. The dots represent the times and locations where the user made or received a call. (B) Shows the same userâs trace as recorded in a mobility database. (C) Shows the same individualâs trace when researchers lowered the resolution of their dataset through spatial and temporal aggregation.
Mobile phone use may be a more accurate identifier of individuals than even their own fingerprints, according to research published on the web site of the scientific journal Nature.Â
Scientists at MIT and the UniversitĂ© catholique de Louvain in Belgium analyzed 15 months of mobility data for 1.5 million individuals who the same mobile carrier. Their analysis, âUnique in the Crowd: the privacy bounds of human mobilityâ showed that data from just four, randomly chosen âspatio-temporal pointsâ (for example, mobile device pings to carrier antennas) was enough to uniquely identify 95% of the individuals, based on their pattern of movement.Â
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âWe show that the uniqueness of human mobility traces is high, thereby emphasizing the importance of the idiosyncrasy of human movements for individual privacy,â the researchers write. âIndeed, this uniqueness means that little outside information is needed to re-identify the trace of a targeted individual even in a sparse, large-scale, and coarse mobility dataset. Given the amount of information that can be inferred from mobility data, as well as the potentially large number of simply anonymized mobility datasets available, this is a growing concern.â
The privacy of mobile data is an increasing concern for privacy advocates and for lawmakers.
Two bills introduced last week in the House and Senate would require law enforcement to obtain a warrant before affixing a GPS device to a vehicle or collecting mobile geolocation data from third party service providers, Wired reported.  And, in December, the U.S. Federal Trade Commission announced new guidelines for implementing the Childrenâs Online Privacy Protection Act (COPPA). Among other things, the changes expand the list of information that cannot be collected from children without parental consent to include photographs, videos and audio recordings of children and geo-location information.
âUnless you get parental consent, you may not track children and use their information to build massive profiles of online behavior,â said FTC Chairman Leibowitz.
The researchers who conducted the work on human mobility say that their work should further inform such legislation. âThese results should inform future thinking in the collection, use, and protection of mobility data. Going forward, the importance of location data will only increase and knowing the bounds of individualâs privacy will be crucial in the design of both future policies and information technologies.â










