Spyware ...

[Dave2002]

I was surprised earlier today to receive an email apparently from Google showing me a "timeline" with places I've been to over the last few years.
It is fairly accurate, but I have no recollection of asking Google to store that data, nor have I any idea how the information was obtained. This seems to go back to around 2013-2014 - before that it doesn't reflect "reality" too well.

OK - allegely it is "private" and I can request deletion - which I may well be inclined to do - but that doesn't actually guarantee that the data will be cleared, does it?!

[Bryn]

The data will, of course, have been gathered from your mobile phone. Unfortunately, smartphones with removable batteries are rare on the ground now, so if your phone is charged . . .

[Frances_iom]

I was surprised earlier today to receive an email apparently from Google showing me a "timeline" with places I've been to over the last few years.
It is fairly accurate, but I have no recollection of asking Google to store that data, nor have I any idea how the information was obtained. This seems to go back to around 2013-2014 - before that it doesn't reflect "reality" too well.

OK - allegely it is "private" and I can request deletion - which I may well be inclined to do - but that doesn't actually guarantee that the data will be cleared, does it?!

if you use an Android phone then that reports home - if a Mac then until Apple prevented it, any use of a Google app could obtain location - location can also be derived by looking at what WiFi base stations are accessible - if accuracy was poor in early days then that might be the mechanism.

[Dave2002]

if you use an Android phone then that reports home - if a Mac then until Apple prevented it, any use of a Google app could obtain location - location can also be derived by looking at what WiFi base stations are accessible - if accuracy was poor in early days then that might be the mechanism.

The recent data is probably from a phone, but some of the data pre-dates the phone, and is probably dependent on integrating data from different sources - such as email - contact to internet hubs, access to web sites, etc.

Interesing your comment that Apple prevented some activity - though I don't feel that makes them whiter than white. Probably some of the data about my travels was from the use of iPads or other kit.