No... Just a forum ban
Probably not a key being revoked for something relatively minor as this, but it is very possible for Badspot to deem your actions bad enough to need to have your key revoked.
How long
/Getting nervous :/
Depends on Badspot himself.
There's not really much precedent and times aren't really given with each ban.
I would estimate a week, but that's pure speculation.
The Host obviously didn't care for the server, or was entirely blind ignorant, in which case, wow...
But, you shouldn't have gone onto the server with the intention of trolling, and if you've gotten Admin for whatever reason, even if it's for something stupid like this, then you shouldn't have permabanned everyone.
Just because the Host has been stupid doesn't mean you should throw all sense of responsibility away and just ruin his server.
