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Cell tower data is much less granular than GPS data collected by apps. Google knows that you were on the same block where a crime was committed, but mobile carr

Cell tower data is much less granular than GPS data collected by apps. Google knows that you were on the same block where a crime was committed, but mobile carriers only know you were in the city or neighborhood.

adrr 5y ago
Mobile carrier location data is near GPS level detail according to the SCOTUS case on it. https://www.supremecourt.gov/opinions/17pdf/16-402_h315.pdf https://www.supremecourt.gov/opinions/17pdf/16-402_h315.pdf
- deleted 5y ago
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- bhassel 5y ago
  A few quotes from that document (from 2018): Each time a phone connects to a cell site, it generates a time-stamped record known as cell-site location information (CSLI). Wireless carriers collect and store this information for their own business purposes. [...] With just the click of a button, the Government can access each carrier’s deep repository of historical location information at practically no expense. [...] With access to CSLI, the Government can now travel back in time to retrace a person’s whereabouts, subject only to the retention polices of the wireless carriers, which currently maintain records for up to five years. Critically, because location information is continually logged for all of the 400 million devices in the United States — not just those belonging to persons who might happen to come under investigation — this newfound tracking capacity runs against everyone. [...] The Government and JUSTICE KENNEDY contend, however, that the collection of CSLI should be permitted because the data is less precise than GPS information. [...] The location records [...] placed [Carpenter] within a wedge-shaped sector ranging from one-eighth to four square miles. [...] While the records in this case reflect the state of technology at the start of the decade, the accuracy of CSLI is rapidly approaching GPS-level precision. As the number of cell sites has proliferated, the geographic area covered by each cell sector has shrunk, particularly in urban areas. In addition, with new technology measuring the time and angle of signals hitting their towers, wireless carriers already have the capability to pinpoint a phone’s location within 50 meters.
nl 5y ago
This understates the accuracy. Cell tower data includes signal strength to multiple towers. The FTC quotes an accuracy of 3/4 sq mile using 3 cell towers, with more accuracy possible in urban areas with more towers: https://transition.fcc.gov/pshs/911/Apps%20Wrkshp%202015/911_Help_SMS_WhitePaper0515.pdf https://transition.fcc.gov/pshs/911/Apps%20Wrkshp%202015/911... https://www.researchgate.net/publication/221568410_Accuracy_Characterization_of_Cell_Tower_Localization https://www.researchgate.net/publication/221568410_Accuracy_... shows a median error of 55m is possible with real-world data from LA.

adrr 5y ago

Mobile carrier location data is near GPS level detail according to the SCOTUS case on it. https://www.supremecourt.gov/opinions/17pdf/16-402_h315.pdf https://www.supremecourt.gov/opinions/17pdf/16-402_h315.pdf

deleted 5y ago
[deleted]
bhassel 5y ago
A few quotes from that document (from 2018): Each time a phone connects to a cell site, it generates a time-stamped record known as cell-site location information (CSLI). Wireless carriers collect and store this information for their own business purposes. [...] With just the click of a button, the Government can access each carrier’s deep repository of historical location information at practically no expense. [...] With access to CSLI, the Government can now travel back in time to retrace a person’s whereabouts, subject only to the retention polices of the wireless carriers, which currently maintain records for up to five years. Critically, because location information is continually logged for all of the 400 million devices in the United States — not just those belonging to persons who might happen to come under investigation — this newfound tracking capacity runs against everyone. [...] The Government and JUSTICE KENNEDY contend, however, that the collection of CSLI should be permitted because the data is less precise than GPS information. [...] The location records [...] placed [Carpenter] within a wedge-shaped sector ranging from one-eighth to four square miles. [...] While the records in this case reflect the state of technology at the start of the decade, the accuracy of CSLI is rapidly approaching GPS-level precision. As the number of cell sites has proliferated, the geographic area covered by each cell sector has shrunk, particularly in urban areas. In addition, with new technology measuring the time and angle of signals hitting their towers, wireless carriers already have the capability to pinpoint a phone’s location within 50 meters.

nl 5y ago

This understates the accuracy. Cell tower data includes signal strength to multiple towers. The FTC quotes an accuracy of 3/4 sq mile using 3 cell towers, with more accuracy possible in urban areas with more towers: https://transition.fcc.gov/pshs/911/Apps%20Wrkshp%202015/911_Help_SMS_WhitePaper0515.pdf https://transition.fcc.gov/pshs/911/Apps%20Wrkshp%202015/911... https://www.researchgate.net/publication/221568410_Accuracy_Characterization_of_Cell_Tower_Localization https://www.researchgate.net/publication/221568410_Accuracy_... shows a median error of 55m is possible with real-world data from LA.