title: Why are special characters displayed as question marks in Facebook posts?
body: <p>When we share links to our magnolia website (running on Tomcat), umlaut characters are displayed as question marks.
  The page head has <code>&lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8" /&gt;</code> and the response header has content type <code>text/html;charset=UTF-8</code> and content encoding <code>gzip</code>. What could be causing the wrong character encoding on Facebook?</p>