BP Filter Activity bbPress posts

// Filter bbPress from updating activity stream
function imath_activity_dont_save( $activity_object ) {
$exclude = array( 'bbp_topic_create', 'bbp_reply_create');

// if the activity type is empty, it stops BuddyPress BP_Activity_Activity::save() function
if( in_array( $activity_object->type, $exclude ) )
$activity_object->type = false;

}

add_action('bp_activity_before_save', 'imath_activity_dont_save', 10, 1 );