I was once votekicked in CT of all places because one person didn't like me being a DPS warrior. I complained to the GM as it obviously fell outside the afk/offline/harrassment trinity, and got the standard form letter with "Grief Tactic" capitalized.

So, feel free to votekick anyone you desire. They won't know you did it. GMs won't do anything about it. The warning on the window is a bluff.