[Discuss] GPS feature in cellphones?

[tmetro+blu at gmail.com (Tom Metro)]

Oliver Holmes wrote:
> ...I understand now that GPS is built in and is
> active whether you activate it or not. So there is the potential to
> track you within three meters. Is this so?

http://arstechnica.com/business/2014/07/9-out-of-10-wireless-911-calls-in-dc-dont-provide-accurate-location-info/

  9 out of 10 wireless 911 calls in DC don't provide accurate
  location info
[...]
  Verizon and Sprint were the best at providing Phase II data, doing so
  on 24.6 percent and 23.3 percent of calls, respectively. Leap was able
  to provide that data on 16 percent of calls. T-Mobile did so on only
  3.2 percent of calls, and AT&T was in last at 2.6 percent.

  The bad results are largely because "[t]he location technology
  currently used by most wireless carriers (called A-GPS) depends on a
  direct line-of-sight to satellites, so it often fails in indoor
  locations or dense urban areas like the District," Find Me 911 said.