I was just wondering the exact same thing.
When I looked at my stats today, I realised they suddenly say I have 1 ban. So, as I never really paid attention to this stat (90% of my kicks are for high ping and the others are for bullshit reasons), I go to the "History page" to find out I got that ban yesterday!
I have no idea where that ban came from. The only servers I played one yesterday are one of my favorites and a handful other random ones.
But I don't remember being kicked, let alone banned.
So I was wondering if there is any way I can find out what server I've been banned from. I'd like to get in contact with the admins to find out what got me banned. Not because I desperately want to be unbanned from some random server, but I am really wondering what has happened.