http://steamcommunity.com/profiles/76561198126105969/
http://steamcommunity.com/profiles/76561198127767660/
http://steamcommunity.com/profiles/76561198126921584/
Each is the profile listed for each of the players, I know this by simply pressing P in game and seeing their names and also looking at last players on Steam and their names matched.
All of them had duped items and were hacking with teleporting/lag/no death etc. Infinite ammo was also another hack they had because he unloaded his magazine into my friend and I and killed us as we could not kill them with his weapon that seemed to never need a reload.