Was having a good round and beating the tar out of the enemy team on Sharqi Pennisula. This included the player I_Soiled_My_Armor. I kept killing him over and over again which prompted him to repeatedly insult me over the chat (this didn't bother me).
Next round rolls around, I_Soiled_My_Armor switches to our team and proceeds to spend the entire round either attempted to and actually succeeding in teamkilling me unprovoked.
I'm sitting in a tank next to my squadmate TolietPastry22... next thing we know we suddenly both explode, both teamkilled by I_Soiled_My_Armor. Turns out he switched teams to our team JUST to intentionally teamkill both me and TolietPastry22 and disrupt our gameplay. Upon asking him "Why did you intentionally teamkill me?". He then began ranting about how I cheated and how I hogged the armor and all sorts of other nonsensical ranting. He then respawns and plants C4 on mine and Toliets armor again immediately. Again I wasn't the only player who was teamkilled intentionally as he also targeted my otherwise innocent squadmate TolietPastry22.
Here's a screenshot of him attempting to justify INTENTIONALLY TEAMKILLING A GRIEFING A PLAYER!
Everybody in the server saw it and people on my own team started coming to my defense with remarks such as "Wow that's lame "I_Soiled_My_Armor" "Bill plays the armor because he's good at it ect.. ect..". This happened around 3 or 4 mountain USMC side Karkand and the server logs will back up as he actually admits to intentionally teamkilling right in the chat. Unfortunatly the screenshot I got of the first actual teamkill itself never showed up on my screenshots folder.

(This is him attempting to justify intentionally teamkilling after he did just that)
At this point SiN the BF2 admin kicked and temporarily banned him from the server to keep him from continuing to disrupt mine and TolietPastry's gameplay by intentionally teamkilling us with C4 but If this disruptive and anti-social behavior isn't deserving of a perma-ban I don't know what is.
I have never experienced anything like this with any other player on sR before. Griefing and intentionally teamkilling two players twice for absolutely no reason whatsoever other than getting owned and frustrated.