By joining the community group on Steam for Payday 2, you can obtain a mask called "Terminator".
The description reads;
"These shades belonged to an assassin from a distant land. The assassin John was sent to kill was built like a machine. This one would prove to be hard. He used a customized Improved Combined Tactical Vest. He was fully armored and very tough. Behind all that armor however, John knew there was only flesh and bones.

John managed to to kill him in the end. He knew however that when he removed him from his place, another would replace him."
This is an obvious reference to the Terminator series with the assassin being the terminator and John being John Connor.