NWO/Mystery

What's this? Noticing the sound of a can hitting the ground. You hear its echo and run to see what it could be. Catching a glimpse of a hooded silhouette, facing a wall and gliding across the floor. You yell out at them. Realizing that you've been watching, the shadow disappears. You realize that the sound, was a spray can and on the brick wall, there's a giant gas mask stencil in front of you. This image looks familiar to you. You black out and only see the letters NWO