Its largely self-moderated, which leads to unfortunate outcomes like bot-voting - for example, I've noticed @zer0hedge will cut-and-paste a story ripped from zerohedge.com, and within a minute or two he'll have 30+ upvotes.

There are other tricks too, like "sockpuppet" accounts, writing supporting comments or articles for other people, giving the illusion that they have a receptive user base. Or simply scamming the potential rewards through upvoting their own comments.

It is "wild west" to a degree, but sometimes major violations of community standards results in higher-level users getting together to downvote an abuser.