When do you bring out the banhammer?

I tend to go case by case and leave the banhammer as a last resource and a tool more likely to protect the community. 

 In general, I tend to start trying to gauge intentions. We all were new to communities at some point and didn't know the netiquette, so typically I try first to PM and explain what is going on and what is expected and go from there, most of the time users are very accommodating. If not then is when I might start considering suspensions if they are being disruptive, by then their intentions should be clear. I rather use tools like thread/post moderation, limiting some tools and maaaaybe a very brief suspension if they need to cool down a bit.

There are times when you can face a well-known member acting out of character and I think it is important to act fast with them. Either they are lashing out because of something happening in their lives (so they might need a gently nudge) or their leashing out because they are unsatisfied with something with your community and that is their protest (in which case I definitely want to know so I can asses it myself). A well-known member, if you leave it to its own, can quickly put a them-versus-us kind of situation against the staff whether because they turn the members against or because the members feel you as staff are failing to enforce the rules for all. It can escalate really fast  and doom the community.

If things are bad to give suspensions, that's when I might follow the 1-2-3 strike system where the suspensions increase in time and the third offence becomes a permanent one. 

Once again, I go on a case by case, so while this is the general idea at the time I tend to go depending on the member actions and response. Banhammer is reserved for the worst, so in general, I am not exactly itchy to use it. 

In all my cases, the banhammer is pretty much needed right away. Since most come on just to spam.

As in the OP, spammers at Christianity Haven are quick to go. The odd member is allowed to remain and if things get too weird we have a private forum where the Admins can work out any posting styles such as too much flaming with that member. We have a moderating protocol in place and try to follow it, but I'm very lenient because I want members to learn what we expect of them instead of just tossing them out.

If its related to spam then i aim to put measures in right away as they have instantly broke the rules and conditions, if it was a long standing member then it would be case by case on warnings etc if carried on then would be a ban if there is any disregard to rules. There is measures such as post reviewing before going live to public, after warnings have been issued if the spam in moderated content then continues we aim to try and work things out directly with the member so they know what can post and what is not tolerated on the site, if it then still continues would result in a ban as we have exhausted all options to try resolve it.

Im pretty much a relaxed admin and give people a chance if they generally have not understood our rules or processes on any of my sites and sites i help maintain.