<p>In order of priority:</p>

<ol>
<li><p><strong>Flag the post for moderator attention.</strong></p></li>
<li><p>Downvote the post.  (As Glen_b helpfully notes in a comment, if you plan to do this, do it first, because if yours is the deciding vote to delete, you won't be able to downvote afterwards.)</p></li>
<li><p>If you have enough reputation, vote to delete the post.</p></li>
<li><p>If you have enough reputation, vote to close it.</p></li>
<li><p>If you have the privileges to edit posts and the post is particularly obnoxious, consider editing out the offensive portions in the meantime.</p></li>
</ol>

<p>Some explanation:</p>

<p>re (1): Moderators respond to the flag by tracking any other "contributions" made by the same individual and dealing with them all at once if necessary.</p>

<p>re (2): When a new user's first few posts are extensively downvoted, that user is automatically blocked from posting more material.</p>

<p>re (3): Posts can be both closed and deleted.  Deletion makes them invisible to most users and so is preferred.</p>

<p>re (5): It's best not to edit a post unless it's obnoxious, because retaining the original text makes it easier for moderators to review it.</p>

<hr>

<p>When a mod is present (which we usually are 24/7 due to our worldwide distribution) then the response to your flag is often swift.  On this site, moderators typically have responded within minutes, if not within seconds, to such material.  </p>
