Every city needs it's law informant. Metro Patrol are the law here in MetroPlex. They have better houses, more hot water rations, and don't have to do time on the wall. But they are implanted with a chip by LabCorp and are monitored at all times.

Some of the civilians say the the chips brainwash those brave enough to sign up. Others say the chips are explosive devices designed to blow up if an out brake within the city walks occurs. But since this has never happened... That we know of. Most are still guessing what the chip is for.