What happens when you are banned ?
If it happens, how do you know you are banned ?
If you can log, what can you and what can't you do ?
Good question I'm assuming that the forums are inaccessible but you can still host streams? Maybe a mod or admin can chime in here because I don't know myself.
For starters, your name is greyed out and when you hover over it it says banned. you're still able to use the site like a logged out user would and you can still do things like change your username, etc.
You can't submit runs, you can't submit forum posts, and I think you can't even like them. (for proof of name-changing, see https://www.speedrun.com/user/MrRacingmonster who changed his name at least twice after he was banned.)