A web application where people can go online and post events they saw taking place and/or ask if other people saw such events. I wagered the biggest draw would

A web application where people can go online and post events they saw taking place and/or ask if other people saw such events. I wagered the biggest draw would be people trying to find out more information on crimes and you could possibly partner with local law enforcement like CitySourced is trying to partner with local government. "My car was stolen today outside of 7-11 between 3 and 3:15. Black dodge truck. Did anyone see anything?" It would be community driven and targeted at locals. I imagined the draw to get people to participate would be to help "clean up" the community. Imagine a centralized resource for people to post about what they saw on 9/11 - assuming the government wouldn't shut you down. UFO's sightings, missing pets, amber alerts could be other such usages. Thoughts? I'm seriously considering developing this if it's well received.