Accoding to this and this, ex-US marine Eric Hall has disppeared after getting up from a Call of Duty 4 session, saying he "had to go" then riding away on a motorbike which was later found running by a Florida roadside.
Hall had been suffering hallucinations and flashbacks, the sherrif's office said, from serving in Iraq. Hall had been seriously injured while on tour, and had been discharged after specding 13 weeks in hospital after being caught in a bomb blast. His friend had been decapitated in the same incident.
So, obviously, the best thing for Hall to do was to play a realistic, modern war game. Don't go wandering too far, Eric.