Care Package

 is a multiplayer killstreak reward in Call of Duty: Modern Warfare 2. After achieving a killstreak of 4, or 3 with the Hardline perk, the player will be given a special smoke grenade that emits red smoke. A helicopter drops a large crate at the point designated by the smoke. This crate can contain a full ammo restock, or any killstreak EXCEPT Emergency Airdrop, Tactical Nuke, or another Care Package. This helicopter can be shot down before dropping the care package.

Advantages and Disadvantages
Care Packages can be quite advantageous in that they can possibly give the player a killstreak that otherwise would take many more kills to earn, most notably AC-130s and Chopper Gunners that don't often, but can sometimes come in care packages.

However, any player, including the enemy team, can take the care package. The player that calls the care package in can capture it almost instantaneously, although any other player (teammate or enemy) must hold down X, square or "F" key (for Xbox360, PlayStation3 and PC respectively) for about five seconds. But should the player be killed while waiting for the package, the results can be disastrous, especially if it is a more deadly killstreak (Pavelow,AC-130, Chopper Gunner, or EMP).

The care package itself can also be deadly. If it lands on top of any player, or simply rolls onto them after touching down, they will be killed.

Caution must be exercised on where to place the care package marker. If placed awkwardly, the care package may land on top of a building or off the map, making it inaccessible (pay special attention on Underpass as many packages land on top of the ruined freeway above).

Further, many care packages simply contain nothing but a simple UAV, Counter-UAV or Ammo resupply. Such rewards are considered "rip-offs", given that for the UAV recon it takes fewer kills to earn than a care package.

Care Packages appear on the radar. Friendly care packages are green while enemy care packages are red.

Content Probabilities
The probability of any given item is as follows (according to PC code): 14.78% - UAV 14.78% - Ammo 13.04% - Counter-UAV 10.43% - Sentry Gun 10.43% - Predator Missile 9.57% - Precision Airstrike 6.09% - Harrier Airstrike 6.09% - Attack Helicopter 4.35% - Pave Low 4.35% - Stealth Airstrike 2.61% - Chopper Gunner 2.61% - AC-130 0.87% - EMP

Tactics

 * Be careful where you place the marker, if its in the open, you can be easily shot down, if it is in cover, it may be out of reach.
 * If it is ammo, which you don't currently have a problem with, leave the package for a teammate to take. Alternatively, you could set a decent trap for the enemy.
 * Watch your surroundings, a sneaky player might sneak up on you and kill you, then take the package for himself.
 * Consider leaving a crate with UAV or ammo alone and ambush opponents that try to get it. Claymores are really effective since the enemy is probably focused on the crate.

While holding the care package marker, players will run at a very high speed and also knife faster than usual. Because of this, some players have built custom classes designed around obtaining a care package marker, and then knifing. An example build:

Primary: Any SMG w/ silencer (usually MP5k or UMP .45)

Secondary: Any pistol w/ Tactical Knife

Equipment: Throwing Knife/Semtex

Special Grenade: Stun Grenade

Perks: Marathon Pro, Lightweight Pro, Commando Pro

Deathstreak: Painkiller

Killstreak rewards: Care Package, Emergency Airdrop, (Any other killstreak)

Trivia

 * Since the 1.05 patch, one kill can be earned from killstreak rewards obtained via a care package that counts towards earning another killstreak reward by the user. However, any other kills scored by a killstreak reward earned via care package will not count. Additionally, any hostile kills scored by crushing an enemy with a care package will count toward the user's killstreak.
 * Though a difficult feat due to the small amount of time it spends on the map, the care package delivery helicopter can be shot down. However, no points are awarded to the player that manages to do so, but will count toward challenges that involve destroying killstreaks (I.E. Cold Blooded pro.)  Care package delivery helicopters can also be shot down before they drop their load. This feat is most easily pulled off if the player positions himself on a high area with a full 360 degree, unobstructed view of the skies. The player will need to pay close attention to his map and respond quickly to the incoming delivery helicopter. If lucky, the delivery helicopter will take a longer route than normal and cross over more of the map than necessary before dropping off its care package. This give's the player an opportunity to shoot it down. When shot down with the care package still attached, the care package detaches from the helicopter and falls down. No points are awarded for this either. Having to concentrate on this one task ruins your game however, and since there are no awards it is usually never attempted by anyone.
 * Like Tactical Insertion, the player can choose to forego using the package, and instead use it as bait for ambushing an unsuspecting enemy. However, the player may be killed by the intended victim(s), who may then take the package for themselves, or even teammates might steal the package.
 * The radius from which players can open a care package actually forms a sphere - allowing some lucky players to capture a care package from underneath it. This can commonly be done in maps like Favela, where Care Packages can land on roofs or other structures.
 * It is generally inadvisable to use the Care Package killstreak on Hardcore game types, as particularly malicious teammates will simply kill you and steal the package. (Unless playing on one of the "Ricochet" game types.) This is even more applicable towards Emergency Airdrops for the same reason.
 * You can NOT get a Emergency Airdrop,Tactical Nuke or another Care Package in a Care Package, contrary to a popular rumour. Infinity Ward has confirmed this.
 * There is a nice tactic for safe obtaining the Care Package. When you throw a marker, deploy your Tactical Insertion near it. Thus, if you are killed by the enemy, you will respawn near the Package, with high chances of killing a foe and obtaining ammo or killstreak.
 * There is a Challenge to be completed when later unlocked under Humiliation to drop a care package on a hostile and winning the match as per last kill.
 * Upon earning a Care Package, some players will take out the marker but will not throw it, forsaking their ability to fire their weapons in exchange for increased mobility and faster sprinting when attacking with the knife. These players are known as mailmen, since they seem like they're trying to deliver the care package to someone.