Hackpick 2000 is a device owned by Lina. It is used to open Locked Chests in a game of Hackpicker. It is shaped like a video game controller with a screen in the center, and a key sticking out of the top. It first appears when Lina shows it to D when he finds the first locked chest in Evil Cave.
According to Lina, the Hackpick 2000 "uses a Visual Basic GUI interface to track down the IP address of the treasure lock". Meaning it uses a graphical user interface coded using the Visual Basic computer language to find the internet protocol address that the locked chest has, in order to hack the chest and open it. However it is not explained how or why the locked chests and the Hackpick 2000 are connected to the internet. This is likely a reference to a CSI episode, where the writers tried to use computer lingo, but failed epically.