Wall Clipping

Currently players can clip through walls and reveal themselves by accident. In a recent game I had an intruder hiding in a room successfully until he turned to look another way and revealed himself to the guards, resulting in the loss of the round. In a similar game I saw an enemy sticking through the wall and was a able to snipe him, dealing 90 damage. I shouldn't have been able to see him, much less hit him. I know it's a difficult issue to resolve, but please work on this; it can be game breaking.