I was playing multi player and we were going thru all the ammo crates. I was learning the back packs and set my back pack down. My mate picked it up. only I could still see it laying on the ground. But he said he picked it up so I went and picked it up. Then we had the same back pack literally. He was in one crate and I was in another. Everything he picked out of the crate was loading into my back pack which was on my back and vise verse. Everything I picked up or dropped from the back pack he could see being added or removed in his back pack on his back.