Head towards the marker located in the central part of the Denny Park. Interact with it to connect to the inFamous Paper Trail profile. IF you have performed all of the steps, connected with the thirteenth mission, correctly (tracking the van basing on its license plate number), you will be allowed to start mission fourteen and it is connected with following the tracked vehicle. Press UP on the D-Pad to start the mission.
Head towards the van, to the North of the starting point, in Waterfront. After you approach the van, it will start going along the highway, to the West. Start following the vehicle, best by jumping over from one rooftop to another, along the Southern side of the route. After it goes off the main road, the car will drive into the alley in Uptown.
Finally, you need to deal with the armed agents near the place where the van was parked. I recommend that you perform an air attack and deal with the remnants, in any way you want. After you have eliminated all of the enemies, you will complete this mission and you will be asked to continue on the inFamous Paper Trail page.