Replicants as an Antagonist

[BaneOfGiygas]

In order to encourage stealth, though, they should have a weakness: their serial-number that, when entered into a new feature in COMMASTER programs, transmits a self-destruct signal. This serial number is stamped prominently on their metal endoskeleton, any time they take significant brute or burn damage, part of their skeleton is exposed and part of their serial-number will be revealed to anyone who examines them.

Or, perhaps more relevantly, require input into the robotics console below the AI core. Only heads (or crafty players) can get in anyways, and it makes a bit more sense given what you're dealing with.