BuddyPress.org

Yay, I found a plugin that disables display names and forces to show the username on all your bbpress. You can find the plugin here: https://bbpress.org/plugins/topic/disable-display-name/

I’ve tested it on bbpress version 1.0.2 integrated with buddypress 1.2.4.1 and wordpress 2.9.2 and so far no bugs.