Sometimes, when someone's having a bad day, their posts will be flagged so all posts must be approved by a moderator. This is considered a cool-down tactic, and isn't intended to be a bad thing. It just means your behavior caught our attention in a slightly negative way, and we want to keep an eye on you. If this happens, just be patient. We will review and approve your posts pretty quickly, or edit them and reply, pointing out what's wrong.
If, however, your actions escalate, you'll get banned. There's no one behavior to point at for this, but basically if you start lashing out, calling people names, making accusations, emailing people nasty messages, or challenging the authority of the moderators, you may end up banned. The basic rule of thumb is don't act like a bad person. You're an adult, you know how to behave. We expect you to, and if you don't, or can't, you will be banned.
Harassing anyone is not permitted, and you will be banned if you do this.
tl;dr: If your posts are being moderated or caught as spam, don't panic, just relax and maybe take a break. We'll still be here.