Forum:How do you kick/ban someone?

Long story short, I also host Crawmerax farming games online. I never had a problem with ninja looters until today. Someone that goes by the name mr.Fieldy wouldn't help with the fight then he would literally ninja loot everything. I don't know how, but his inventory had like 999 slots.

I got tired of him being an ass so I tried to ban him. I hit esc...went to view game lobby...then I noticed there is no option to kick or ban anyone.

Is there a way to kick or ban someone or prevent someone from a certain IP address connecting to your server? A console command perhaps?