I've only found one. One other time, I found a green square surrounding a building on the map and I got the "Citizen E is near; find him" message. I must have run around that building twenty times with no luck.
Any help?? I finished the story, but I can't help but feel gypped by the fact that I didn't find any more than one Citizen E before the ending.
I believe that Citizen E is actually up on the building. If you're talking about that really really big building in the game. I think it's like a church or something. There was a synch point up there as well if I recall correctly. Climb up to the top of the building to find that Citizen E. I found all but one myself. One day I might go back to looking for that last one.