Pause Guardian

The Unitroller contract designates a Pause Guardian address capable of disabling protocol functionality. Used only in the event of an unforeseen vulnerability, the Pause Guardian has only one ability, to disable a select set of functions: Mint, Borrow, Transfer, and Liquidate.

The Pause Guardian cannot unpause an action, nor can it ever prevent users from calling Redeem, or Repay Borrow to close positions and exit the protocol.