BuddyPress.org

This should be an admin option, and will likely be added sometime before the first release. Right now the easiest way to stop this is to modify the bp_user_fullname() function as this will change it everywhere.

Line 243 of bp-xprofile-templatetags.php

function bp_fetch_user_fullname( $user_id = false, $echo = true ) {

global $bp;



if ( !$user_id )

$user_id = $bp['current_userid'];



$ud = get_userdata($user_id);



if ( $echo )

echo $ud->user_login;

else

return $ud->user_login;

}

This is just a temporary solution, and it will break in the future. It should tide you over until a better option is available.