Left4Dead2 Visuals Multihack

Do you have a bind of some kind that you press accidently?
Theres some known ways to lag servers by spamming console commands like ping or status
So if you type too many commands at once, you should get kicked for this like that

ok, i know now..

This typically only happens on Unofficial Servers, Dedicated Servers dont kick based on the amount of "commands" executed. So, in the Unofficial Servers as a way to combat cheating they kick you if you try to use your cheats.