User blog comment:Crazy sam10/Call of Duty 4: Modern Warfare ‘Stat Reset Tool’ now avalible for Xbox 360 players/@comment-189.222.88.230-20130405024734/@comment-142.162.22.42-20130409103436

If you are talking about Mob of the Dead, there is a big riot zombie that can shut down perks and you need points to reactivate them.