Methods, systems and computer program products for filtering generally-broadcast messages received by a movable unit based on current spatial position, stored trajectory history, and probable future trajectories. A current spatial position of the movable unit is received and stored to form a stored trajectory history. A generally-broadcast message relating to a target geographical region is also received and stored. Potential trajectories of the movable unit are then computed over a pre-determined time based on at least one of the current spatial position, a current travel direction of the movable unit, and the stored trajectory history of the movable unit. The generally-broadcast message is then disseminated in response to at least one potential trajectory crossing into the target geographical region during the pre-determined time period. The generally-broadcast message may also be disseminated on the basis of specified user preferences.