I think another interesting topic would be how certain OpenStreetMap editors safeguard their edits by adding unique characteristics. This would help identify if some commercial map service providers are violating the OSM license by taking data. From what I recall, this topic sometimes comes up in discussions among local OSM editors. However, I don’t think they would disclose these tricks, as doing so would make it public, and those who unethically copy from OSM could then filter it out.