Along the bottom of posts you'll find various links. One of these is "Flag as Offensive", for example. If enough people click on that link, the post will be unpublished. The number required for that to happen will remain a secret so as to not encourage manipulation of the system. We may use other flags in the future as well, and I'll update this post to reflect what they are for and what happens when they are clicked. The difference between unpublishing and deleting is that an unpublished post is still in our system so we can review it as opposed to removing it from the database entirely.

Summary:

"Flag as Offensive": Unpublish post when flagged enough times.
"Flag as Spam": Delete post when flagged enough times.