There is just the problem, that you might get a lot of duplicates, if the same entry exist on different platforms (and this happens quite soon, as visionary entries are on many maps). And for editing one entry, you have to register or notify the owner-plattform(s).
Merging and Editing
If you want to avoid duplicates, you have to merge several entries and aggregate all information into a final one. This is only possible, if all entries are CC0 (Creative-Commons whithout limitation) or ODbL (Creative-Commons share alike).
You can not compare and merge those entries with a „read-only“ licenced entry, as the result will always be a modified, improved information of this. When ever you use a „derivative work of the Database“ you have to relicense it again in the same licence (that means share alike).
The question is: If I just compare a raead-only (CC BY-ND) entry and a share-alike (ODbL) entry, and hide the first one when realizing it is a duplicate, without using any of the information (except that it is a duplicate), is this allowed? ( The licence sais: If you remix, transform, or build upon the material, you may not distribute the modified material.) Do I build upon a duplicate, if I just `compare and delete it?
you claim „Transiscope does not redistribute data“. but that’s what Transiscope mainly does, it collects data from different sources and offers this data in a unified format (not the original!) via their interface. In my understanding this is a change by format conversion and redistribution via API.
And do you know the licence, under which they redistribute the data?
Stadtwandler claims, they would not redistribute the data, or at least, not modified or in a different license than the initial datasource.
Transiscope verfolgt eine Creative-Commons strategie wie die Karte von morgen. Einen Überblick über die genauen Lizenzen scheint dort keiner zu haben, aber sie wollen auf jeden fall beidseitige Syncronisation wie kvm in DE. Alles unter ODbL.