blockquote>
      The security model of the web is based on the concept of "origins", and correspondingly many
      of the potential attacks on the web involve cross-origin actions.
    </blockquote>
    <blockquote>
      When accepting untrusted input, e.g. user-generated content such as text comments, values in
      URL parameters, messages from third-party sites, etc, it is imperative that the data be
      validated before use, and properly escaped when displayed. Failing to do this can allow a
     