Liddy

Liddy was an associate of Graham Bauer, possibly connected to the Bluetooth cabal, who was monitoring Phillip Bauer's house on Day 6.

Day 6
Around 10:25 AM, Liddy intercepted a phone call between Jack Bauer and the Bauer family's servant Sam. Liddy, who seemed to be in another room of the house, called Graham to warn him that Jack had been released by the Chinese and that he was looking for their father.