We will try to answer questions as they arise.
Doesn't twitter and instagram mark your location for you? Why do you need a hashtag to say where you are?

The purpose of this hashtag system is that you are actively telling people that you are reporting news from the location that you are at and users are actively searching for reports from that location.

Also twitter won't show your location unless you've opted-in to the feature, and have allowed your device or browser to transmit your coordinates to them. Here is a link to twitters information about turning on and off the location feature.

There is a site calles Nearby tweets where you can search for tweets from a specific place. Great service but not news related.