Infiltration

Infiltration is a way of getting eyes and ears on a target, as opposed to fangs and claws. It's an ongoing state rather than a one-time event.

Acquiring Infiltration
Agents can Infiltrate POIs via Challenges. Indeed, one of their six stats is named "Infiltration." Posting in the Bay 12 Games Forums, King Dinosaur Games laid out three tiers of Infiltration that subvert ever more influential members of society. Belial, the beginner's Old One, comes with the ability to use carrion-eaters as his spies and gain Infiltration without using Agents.

Leveraging Infiltration
Infiltration provides information: posting in the same, KDG stated that it's "mostly to see internal political maneuverings and to see what heroes are doing." Infiltration also opens up nefarious ends, such as using an Infiltrated city guard to imprison a Hero. An Guild can be Infiltrated to "provide a spy in every POI with that guild in it", and then overthrown.

Losing Infiltration
Posting in the same, KDG stated that pushing an Infiltrated target to act risks expending it; the act generates a Quest. Heroes or Nations may also hunt down the Old One's influence.

Infiltration And Heroes
King Dinosaur Games has mentioned that gaining Infiltration on a Hero involves corrupting the Hero, corrupting the Hero's friend, or making friends with the Hero.