It seems Thornhill Industries has been on a hiring spree.
”
— Harold Finch
Thornhill Corporation is an organization founded by the Machine under its "Ernest Thornhill" alias. Its function is to serve as a human face and a cover for operations such as hiring and purchases conducted directly by the Machine.
The Thornhill Corporation was created sometime before the events of “Zero Day” as the product of the Machine's survival instinct. As Finch programmed it to delete its memories daily, the Machine needed a way to preserve them. So it created a data entry orginazation: at night the Machine would print out its memories and during the day, employees would input the code back into the Machine.
2015[]
Thornhill Utilities, the utilities branch of the Thornhill Corporation, covertly installed and maintained data nodes the Machine used to move itself to the U.S. power grid. (“YHWH”) It is also mentioned that the boxes mustn't be opened, and when an employee did so, he disappeared at the next day.
2016[]
In “Synecdoche”, a Thornhill employee supplied a cover identity to Shaw.
In “return 0”, a group of bribed cops preparing to execute Reese and Fusco, were taken out by a team of snipers, hired via Thornhill.