It's an administrative toughie. Especially if your main tenet is (as it was for me and I think should be for you) "civil future conduct; not punishment for past conduct".
I used to take the same approach to multiple accounts as you. And if I terminated the account for good reason and they were only using the new accounts to circumvent that, I'd terminate the new accounts, too. But eventually I evolved that to more like "Let's talk about your conduct and if you'll straighten it out, I'll let you have a new account but if you cross the line with that one, that account and any new ones you make will be terminated."
To me, the multi-account ban should be mostly focused on one thing: Using multiple personas to manipulate a stock by giving the appearance of multiple people liking/disliking it. That's where the rule originated at SI. To stop one form of manipulation. Later it evolved to "also don't use multiple accounts to circumvent a suspension".
Which leads me into a sort of new topic. Suspensions and expirations of same.
You would probably be very surprised to know that at SI, warnings were counterproductive more often than not and suspensions were usually productive.
Put yourself in the warnee/suspendee's shoes (which should be a habit for the Admin) and consider which is going to be met with the most resistance:
1. An automated "Your posting privileges have been suspended for 3 days for the content of this post: [post here], which is a violation of our Terms of Service in that it [cite relevant TOS item here]. You will be able to post again after [suspension expiration date/time here]. If you feel this suspension is in error or that there are facts about this suspension I'm unaware of, email me at [email addy here]."
or
2. "Dude, you didn't really break any rules of the site, but you're getting close there. Please back off the personal attacking nature of your posts. You should be talking about the stock in question, not your fellow posters."
Don't even get me started on the "You didn't break any rules but you're suspended" thing.
In my experience, warnings of any kind usually resulted in conduct that would end up in a suspendable rules infraction.
You'd be amazed how much email I got after a suspension that said "You're right. That post was a bit over the line. I'll do my time and quit posting drunk." or "I'll cool my heels for a bit and when I can post again, I won't do that again."
I had an unwritten and hopefully largely unknown policy with first-time offenders that if I got an unsolicited email like that from them, I'd immediately remove the suspension.
And if I didn't, it would expire at a time that the user knew it would expire.
It's awful not knowing when a suspension is going to expire or the reinstatement of your posting privileges being left to the whim of someone you don't even know.
Granted, it's our house and there is no "First Amendment" here, so we can pretty much do whatever we want, but I think it helps the site's credibility, eases a lot of the Admin workload (easier to just slap a 3-day on someone than to negotiate their release), and makes violators of the rules more inclined to not be future violators if there's an immediately known end in sight to their suspension.
Also, there was another aspect of my job that was really helped by being able to slap programmatic suspensions on people.
The first thing I did every morning was review each suspension I'd done the previous day to see if I still felt they should be suspended. Sometimes I'd lift a suspension right then or reduce it. I'd never increase it unless they were being abusive to me via email.
As the site grows, I really don't think it's workable for you to just keep all the suspensions/terminations in your head and you'll lift them when you think you should. I really think you should almost always be putting a timeframe on every suspension and when that time has elapsed, the system restores their account.
I had wonderful admin tools at SI (thanks to Brad, who understood the importance of making the process as objective, easy, and automated as possible) and I can the same tools here. Things like administrative notes for each account, and tracking of previous suspensions so you don't have to try to remember whether or not someone was previously suspended and for what.
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