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North Carolina Police Obtained Warrants Demanding All Google Users Near Four Crime Scenes (wral.com)
An anonymous reader quotes the public records reporter from North Carolina TV station WRAL:
In at least four investigations last year -- cases of murder, sexual battery and even possible arson at the massive downtown fire in March 2017 -- Raleigh police used search warrants to demand Google accounts not of specific suspects, but from any mobile devices that veered too close to the scene of a crime, according to a WRAL News review of court records... The demands Raleigh police issued for Google data [in two homicide cases] described a 17-acre area that included both homes and businesses... The account IDs aren't limited to electronics running Android. The warrant includes any device running location-enabled Google apps, according to Raleigh Police Department spokeswoman Laura Hourigan...
On March 16, 2017, a five-alarm fire ripped through the unfinished Metropolitan apartment building on West Jones Street... About two months later, Raleigh police obtained a search warrant for Google account IDs that showed up near the block of the Metropolitan between 7:30 and 10 p.m. the night of the fire... In addition to anonymized numerical identifiers, the warrant calls on Google to release time stamped location coordinates for every device that passed through the area. Detectives wrote that they'd narrow down that list and send it back to the company, demanding "contextual data points with points of travel outside of the geographical area" during an expanded timeframe. Another review would further cull the list, which police would use to request user names, birth dates and other identifying information of the phones' owners.
"Do people understand that in sharing that information with Google, they're also potentially sharing it with law enforcement?" asks a former Durham prosecutor who directs the North Carolina Open Government Coalition at Elon University. And Stephanie Lacambra, criminal defense staff attorney at the Electronic Frontier Foundation, also criticized the procedure. "To just say, 'Criminals commit crimes, and we know that most people have cell phones,' that should not be enough to get the geo-location on anyone that happened to be in the vicinity of a particular incident during a particular time." She believes that without probable cause the police department is "trying to use technology as a hack for their job... It does not have to be that we have to give up our privacy rights in order to participate in the digital revolution."
Nathan Freed Wessler, staff attorney with the ACLU's Speech, Privacy and Technology Project, put it succinctly. "At the end of the day, this tactic unavoidably risks getting information about totally innocent people."
On March 16, 2017, a five-alarm fire ripped through the unfinished Metropolitan apartment building on West Jones Street... About two months later, Raleigh police obtained a search warrant for Google account IDs that showed up near the block of the Metropolitan between 7:30 and 10 p.m. the night of the fire... In addition to anonymized numerical identifiers, the warrant calls on Google to release time stamped location coordinates for every device that passed through the area. Detectives wrote that they'd narrow down that list and send it back to the company, demanding "contextual data points with points of travel outside of the geographical area" during an expanded timeframe. Another review would further cull the list, which police would use to request user names, birth dates and other identifying information of the phones' owners.
"Do people understand that in sharing that information with Google, they're also potentially sharing it with law enforcement?" asks a former Durham prosecutor who directs the North Carolina Open Government Coalition at Elon University. And Stephanie Lacambra, criminal defense staff attorney at the Electronic Frontier Foundation, also criticized the procedure. "To just say, 'Criminals commit crimes, and we know that most people have cell phones,' that should not be enough to get the geo-location on anyone that happened to be in the vicinity of a particular incident during a particular time." She believes that without probable cause the police department is "trying to use technology as a hack for their job... It does not have to be that we have to give up our privacy rights in order to participate in the digital revolution."
Nathan Freed Wessler, staff attorney with the ACLU's Speech, Privacy and Technology Project, put it succinctly. "At the end of the day, this tactic unavoidably risks getting information about totally innocent people."
The 4th Amendment is pretty clear that warrants should only be issued on having probable cause. What they asked for sounds very much like the general warrants that are explicitly banned by the same amendment.
The GPS chipsets in phones are far and away the biggest sellers of GPS chipsets. With additional specialisations for reducing power (compared to the Garmin GPS which I had in the early 2000s). But why would a phone track fewer satellites than (say) 15kg of suveyor's GPS with a differential base station and another 5kg of battery for each station? Partly for power use - each received signal and decoding cost miliwatt-seconds of battery power - and partly for speed of response.
Three satellites will give you a ground position. Actually, three satellites will give you the crossing point of three arcs of position solutions. Which almost certainly will not cross, but will define a triangle (*) on the ground. What is the probability of the true ground position being inside that triangle ? 12.5% - 1 in 8.
That is why GPS systems are more accurate with more satellites, and why they strive to acquire as many satellites as the system can handle.
The same problem applies to getting an altitude, for which you need a 4th satellite. It's actually a bit worse, since the system is optimised for ground positions not altitudes, so the uncertainty in altitude is almost always bigger than for ground position. (*) triangle - with arc of a conic section edges, not straight lines. But it doesn't change the argument, just makes the geometry much more complex.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"