So, most people figured out a long time ago that if you bind zoom to a different key, LeftShift essentially becomes the "walking mode" key. This still works in the single player beta, but not in multiplayer. I'd suggest adding an option to bind walking to a key, having the effects of slower movement (and activation of the walking animation), increased accuracy compared to running, and quieter footsteps. I know it's not a huge priority, but it shouldn't be too difficult to implement.