I use Citizen app, which is very useful for reporting nearby safety incidents in (dense American city) where I live... One interesting aspect of it is that it incentivizes "going live" to capture live video of nearby safety incidents, I think it actually pays out people for doing so.

To me, this could 100% be "nostrfied"... Set up bounties for your geohash, and when incidents are reported, you incentivize real-time reporting.

On the other hand I think part of their "moat" is that they're scanning police and fire radio, and using AI to transcribe and categorize the calls...