If Forum is Unread?

I’ve googled the snot out of this one:

Do you have a hook in place that can be used to conditionally display things in the theme such as a is_forum_read()?

It would be nice to do..

if(!is_forum_read($id))
  {
  ?> <img src="/readforum.jgp" /> <?php
  } else {
  ?> <img src="/unreadforum.jpg" /> <?php
  }

http://wordpress.org/plugins/bbpress-mark-as-read/