[OSM-dev] Working with OSM data with less or no metadata

[Christoph Hormann]

On Wednesday 14 February 2018, Darafei "Komяpa" Praliaskouski wrote:
> >
> > While this seems a useful test to do i wonder how the timestamp and
> > version fields are relevant regarding privacy and personal data
> > protection?
>
> If OSM API were fast enough, it would allow to rather easily group
> changes back to changesets. Number of changesets gets you back number
> of mappers. Classifying a returning mapper by edit pattern would
> allow to get back the geometric median of their edits, which brings
> you to knowing where they live.

No, even if the API was infinitely fast limited bandwidth and the 
possibility to append new edits to existing open changesets would make 
this impossible.  

And even if you could identify the changeset a certain feature was last 
modified in that would still not allow you to conclude which changesets 
are created by the same user.

If you practically want to reverse engineer user identities from a 
planet file with user info stripped looking at the data itself and 
mapper specific data charateristics (tag combinations, the way 
geometries are drawn) would likely be more useful than versions and 
timestamps.

-- 
Christoph Hormann
http://www.imagico.de/