If I saw someone locking in GZ now I would probably tell him that he could get banned for it. If he stops doing it I would just warn him about what could happen because, he might be new and confused aswell. But if he kept trying I would printscreen or call an admin.
I wouldn't do the mistake and...
Dear Admins
Hampus has opened an un-ban appeal
Your In-game name: Hampus
Your Steam Profile ID: 76561198008862026
Your GUID or Steam ID: b0fb656e283a276952b6af9ae4651cd3
Date & Time you was banned:: 2015-09-19
Admin that banned you (Check ban message when you connect to the servers)...