Me n David were screwin around in my nerdy server (It's been up for 5 hours) and we found out that you can freeze the combine balls. Not sure if this has been known before and I know it doesn't matter much since it just blows up in like 5 seconds... Still fun if your using a cheating match (without buddha/godmode) and you want an alternative way of stopping/reflecting the ball insted of using GG.
The original poster is talking about the plasma balls -the secondary fire mode of the combine assault rifle.
//EDIT
The line "since it just blows up in like 5 seconds" from the original post should have cleared up any ambiguity about whether the post was in reference to the flags or the plasma balls.