[OSM-talk] License plan

[MP]

>>I think we should find some way to avoid deleting at all. For some
>>transitional time (in which the data will be still under cc-by-sa but
>>we will be collecting consent of users for ODbL) mark data coming
>>from/derived from people uncontactable/disagreeing with license with
>>some special tag. Let people delete these parts and redraw them from
>>scratch (from allowed sources/existing GPS tracks, anything except
>>the original data).
>
> You would have to be very careful about doing that.  I don't think it
> would work to view the map, see a street tagged 'bad licence', delete
> it and then add it back.  Even if you were honest enough to close your
> eyes, turn around three times and then re-trace it from the aerial
> photography, it still looks very suspect.  And when deleting the
> street you would have to delete all its nodes, including those that
> are intersections with other streets, since it obviously doesn't do
> anything to delete the way but leave all the nodes there to be
> straightaway reconnected.

Sometimes (if current data are drawn very inaccurately and do not
contain any valuable tags like name, etc..) I do this - delete current
data, then draw it again from scratch from aerial photography with
greater accuracy. It is faster than trying to move existing vertices
around, splitting and merging the ways in the process.

Yes, you have to be very catious when redrawing, but I think it may be possible.

> Try this thought experiment: suppose a user imported data from Google

Well, this is disallowed completely in first place. But here we have
good data, just under different (but similar) license.

> Since the reason for relicensing is to be ultra-cautious and take care
> of certain theoretical legal bogeymen, it makes sense to be ultra-cautious
> in removing possibly tainted data.  There is no point doing a relicensing
> that leaves the project in a more questionable legal situation than before.

Well, but how can you then explain to users that half of the data is
lost just due to small incompatibilities between cc and odbl?

Also, technically, when "mixing licenses", we won't have mashup of
cc-by-sa and odbl, we will have mashup of cc-by-sa without consent to
relicense later under odbl and cc-by-sa with consent to relicense
later under odbl. I think such "mashup" could work for short time
(before we persuade all to get consent or delete and replace their
data if we have no consent), once we have all "cc-by-sa with consent
for odbl", we can just switch to odbl.

Martin