Case of the Missing Scholars
This video begins by demonstrating a cheat: You can make Informers shut up (both before and after the mission) by dropping onto them or by jumping into them and pulling Left Trigger while in mid-air. The same tricks work on Saved Citizens.
After the blitz assassination mission (42.84 seconds), the Informer tells Altaïr about a certain set of Scholars who aren't all they're cracked up to be. The Prima Guide shows a Save Citizen at the Scholars' location on one map, but not others. I believe it's an oversight in the game design.