Also worth seeing is Google's Location History. For me it has come in handy a number of times when I'm trying to figure out the exact time I left or arrived somewhere.
Where do they get the data? I just checked mine and have nothing for the last 30 days. But I only sparingly log in to Google in an incognito window, don't have the Google apps on my Android phone, don't use Google Maps much, etc., so I didn't expect anything.
Also, does anyone have a good solution for tracking yourself, for purposes like reconstructing the time/date you were somewhere? I used a GPS logging app for awhile, but I don't remember if I ever even looked at the data. I had concerns about battery life, and how to use the data even if I got it reliably and efficiently.
Thanks for the reminder. I never clicked through to my location history before, even though I abstractly knew it existed. Quite an eye opener seeing your daily movements plotted on a map.
I have a friend who is a first-line tech support for a local cell-phone carrier (Rogers Wireless in Canada). He once lost his cell phone on a camping trip. He just logged on to his system and checked for a "ping" from his cell phone and triangulated the exact location.
My point is...this guy is just a front-line tech support and he has access to find the exact location of any given cell phone. So when they say "he makes calls from this tower so he must be home"...they actually have a lot more information available than just which tower was used.
IANAL but these observations are all location related. The police don't need a warrant to follow you (I don't think). Isn't observation by tracking your phone a lot like that? A detective following you could also observe private details about your love life and your place of worship.
Yes, one detective can learn a lot about one person's life in a given timeframe by actively following them. That's different from X00,000 detectives who never sleep and can follow everyone, everywhere, constantly, at very low cost. People/agencies with access to these "detectives" can "retroactively follow" people, something not possible with the lone human detective. IMO there's a huge difference in both quantity and quality of this tracking.
Walking speed taking twice as usual? Possibly bad health.
Beyond the obvious about who you know and hang around with (both, often, at the same place), what your interests or politics are (every friday, he is the vicinity of that ACLU gathering place), etc, etc. ..And I haven't even tried.
https://maps.google.com/locationhistory/b/0