A new glitch with the MW3 ‘kicked for inactivity’ feature is incorrectly removing players who are using a Killstreak!
Call of Duty games have a feature that kicks players from matches if they aren’t playing the game. While this is usually very handy, as it ensures that teams don’t have players who are AFK, MW3 seems to have taken this too far.
You can’t even use Killstreaks anymore without fear of being kicked!

Players Using Killstreaks Are Being Kicked For Inactivity
Many MW3 players are reporting being mistakenly kicked from games while using Killstreaks. This includes the Gunship, Chopper Gunner, and manually controlling a Sentry Turret.
The issue is likely because your character doesn’t move while using these streaks. However, Modern Warfare 3 seems to have forgotten to take this into account when deciding to kick players who are stationary!
The first example shows a player being kicked for inactivity while still piloting their Gunship. This is certainly very frustrating but somewhat understandable, as the player’s in-game soldier will not be moving while piloting it.
However, even after you have finished using your Killstreak, you still might not be safe. Another clip on Reddit shows a player being kicked for inactivity even after finishing using their Chopper Gunner and beginning to run.
It is also worth avoiding the manual control option for Sentry Guns, as that could lead to you being kicked, too!
To make matters even worse, some players have also reported being kicked for inactivity when sniping. Therefore, you should be careful if you plan on staying in the same spot when lining up headshots.
Hopefully, MW3 developer Sledgehammer Games will address this Killstreak kicked for inactivity glitch soon. However, until then, you may want to avoid using the affected Killstreaks.
Luckily, it should be quite an easy fix, so expect to see it included in an update in the near future!