Knowledge is imparted to spies on how to be on the lookout for the time they are under observation. In a car, this may mean taking turns a lot or driving to the country so as to check whether a tail is present. When on the street, the eyes of a spy would be searching for individuals who appear like they may be too concerned about their actions.

However, it is a lot more difficult to detect “ghost surveillance.” This kind of surveillance is “very secretive and apparently omnipresent.” This is stated in the manual that checks the target until it cannot be seen anymore.