Which is probably why certain topics get swiftly disappeared from the front page. Although I'm sure there is/was work underway on tools to automate this.
Most large subreddits run AutoModerator to pre-filter submissions.
In terms of submissions getting to the front page and disappearing, that's a different issue entirely than insider privilege (namely, highly selective rule enforcement). The subreddit /r/undelete captures these incidents.
AutoModerator, by far the most popular reddit moderation automation solution, was integrated with reddit about 8 months ago[0], making it "official". It has lots of options, i haven't played with it that heavily
