[OSM-legal-talk] Is the "data share-alike" road navigable?

[Richard Fairhurst]

Tom Chance wrote:

> Also, how would we know if someone was using our database unless we  
> put easter eggs in? It seems fairly toothless to me, it's much  
> easier to see that
> someone is using your slippy map tiles or drawing on your bespoke  
> walking
> routes map.

This Easter egg thing is a bit overstated.

They do exist, sure - as recorded on our wiki. But you don't need  
Easter eggs to prove copyright infringement. Any geodatabase, or map,  
of sufficient size will contain so many matters of judgement anyway -  
should I include this road? Should I include an apostrophe in this  
town name? Did I use the spelling from this street sign or from that  
one? Where should I put the label? - that the sheer weight of  
coincidence will prove infringement.

(As an example, if someone were to make a map of Charlbury using OSM  
data, I can spot three such judgements straight off that would give  
its provenance away.)

The reason people insert Easter eggs is that they make the proof  
easier: they provide certainty, and lawyers like certainty*. But you  
don't _need_ them.

cheers
Richard

* actually, people who pay legal bills like certainty. Lawyers find  
uncertainty more lucrative.