This is a fairly specific but somewhat useful exploit using the IMS.
For this to work you must have Assault killstreaks on with an IMS. For it to be useful, you need at least one killstreak to be higher than IMS (5)
1. Get an IMS, 4or5 kills, depends if you have hardline on.
2. Don't bother to suicide, but DO NOT place the IMS just yet. and wait till your next life.
3. On your next life start killing and get 3or4 killstreak points (1 below rewarding you your IMS)
4. Place your previous life's IMS somewhere.
5. Get another kill to earn a new IMS.
6. Get kill points from the first IMS towards your current life's killstreak.
A few extra details:
- i do not know for sure if you can have two IMS out, so don't place the new one until you have used the old one, but both will count.
- Stealing someones care package that is an IMS would probably also count (as long as you have IMS on your killstreaks, and it is earned on your current life)
Basically the game does not differentiate between the IMS and just reads the player has IMS earned and active and received a kill from one, rewarding you points. So technically you can get 8 kill streak points in one life from IMS (possible 12 or more if you can use a care package IMS and have it count)