Embodiments include a system, method, and computer program product that enable intelligent formation and management of dynamic talk groups. Embodiments include a discretionary sharing mechanism based on invitation and acceptance that allows for dynamic publication or sharing of information in real time among agencies responding to an incident, where the agencies may establish secure communications. Additional embodiments include establishing and associating geographic boundaries of incident sites with talk groups, monitoring conditions that trigger warning messages sent to talk group members, and subscriptions to information channels that allow multimedia information to flow into talk groups.