[fixermark]

Personal opinion: the fact that type of sharing hasn't happened with open source services speaks volumes about the priorities of the open-source communities and is the single-biggest argument in favor of allowing large corporations leeway to create big cool things with big data. I don't see anyone else stepping up to solve the hard problems like this.

[acover]

Have there been open source projects that had the opportunity to and decided against it?

[fixermark]

OpenStreetMap currently exists. Is there an open-source search engine out there that could try to integrate with them?