Multiple different accounts were created and used to upvote his own stuff and target other users with downvotes. This is the second or third time a user has been banned for vote manipulation, and as far as I can remember, the only reason aside from spamming that a user has ever been banned. Please do not create alts for the sole purpose of giving yourself more internet points, it's pointless and we will be able to find out if it's happening.
In the future, we could implement account restrictions to try and curb this. Currently we have no restrictions on freshly created accounts, other than sub creation and captchas for posting. We could maybe add up/downvote restrictions based on age of account or account level.
But yeah, thought it would be best to make a note of the banning rather than explain what happened in a couple of weeks if someone asked where he went.
PS: No, the irony of making this post on an admin alt is not lost on me.
This interpretation does match up with the posts/users/comments etc. that had votes applied. At the end of the day the reasoning behind it doesn't matter, accounts were made for voting reasons, and that's all we know.
Also going to reply to @Sarcastaway here. It is a shame he was banned, I enjoyed talking to him from time to time and he made some decent posts. I do think though that the best way to stop this kind of thing from going on is to not make any exceptions on bans for doing it. Honestly, things could have gone differently if he had owned up to it, but he denied doing it when asked directly by @Polsaker, and even went as far as continuing to message us asking for our logs.