Call of Duty Modern Warfare has got several modes and here we are talking about one of them, Infected. In this mode, there is a trick that will allow you to get many kills.
This trick is absolutely legal but get ready to accept negative feedback from your friends, because it's a full-blown betrayal. Of course, kills are assured.
When you are running this mode and you are one of the survivors make sure to dig in with your friends in a raised area that is outdoors. This tends to happen naturally, as the Infected mode itself encourages players to work together in hard -to-reach areas to try to survive the aggravation of those infected.
Get a streak of air attack casualties and when you see that your teammates are grouped together, launch the attack in the same area as your team and yourself. Then jump and / or commit suicide with a grenade.
This will turn you into an infected and therefore, the friends who were in the building will become enemies. The airstrike will execute and kill what was your team, giving you a good amount of points and many casualties. This occurs because once you die, friendly fire disappears because you now belong to the opposing team.