Two people are required for this glitch. For added PP Boost, this trick is best done with the Rescue magazine, which is found in the Arena Security office. This office only be accessed during or after mission "Insecurity". Locate any magazine you wish to duplicate and have it in your inventory. Save your game, then have a friend start their own game and locate the same magazine. Either invite your friend or join them in their game, but from the in-game friends list and not from the main menu. When you arrive in their game or they arrive in yours, they will bring their inventory over with them. The person who joined will then quit, dropping their inventory for the second player to pick up. The person who quit should then reload their own game, and still have their inventory items. They can rejoin and either pick up any items the host has not picked up, or repeat as much times as necessary to acquire the desired number of items. If done with the Rescue magazine, then times it will result in a total of 250% bonus PP to survivor activities (Join and Escort bonuses), which can get you somewhere in the range of 10 million PP in a single playthrough.