Privacy lock mechanism

A lock device that prevents operation of at least one chassis spindle from retracting a latch bolt, and which may provide auto-unlock features. Locking of the lock device can effectuate linear displacement of a slider body from an unlocked position to a locked position. Linear displacement of the slider body is translated into rotational displacement of a cam body that includes, or is coupled to, a locking shaft having a cam protrusion, thereby rotating the cam protrusion. As the cam protrusion rotates, the cam protrusion lifts a locking lug to a locked position wherein the locking lug prevents rotational displacement of a first chassis spindle. When in the locked position, a slider arm of the slider body can be positioned in a retention slot. Subsequent rotatable displacement of a second chassis spindle can effectuate displacement of the slider arm from the retention slot and facilitate unlocking of the lock device.