bp_activity_has_activity_filter( $has_activities,  $activities )

function bp_activity_has_activity_filter( $has_activities, $activities ) {

	if ( ! bp_is_active( 'friends' ) || ! is_user_logged_in() || is_super_admin() ) {
		return $has_activities;
	}

	if ( ! empty( $activities->activities ) ) {
		foreach ( $activities->activities as $key => $activity ) {

			if ( 'friends' == $activity->privacy ) {

				$remove_from_stream = false;
				$is_friend          = friends_check_friendship( bp_loggedin_user_id(), $activity->user_id );
				if ( ! $is_friend ) {
					$remove_from_stream = true;
				}

				if ( $remove_from_stream && isset( $activities->activity_count ) ) {
					$activities->activity_count = $activities->activity_count - 1;

					if ( isset( $activities->total_activity_count ) ) {
						$activities->total_activity_count = $activities->total_activity_count - 1;
					}

					unset( $activities->activities[ $key ] );
				}

			}
		}
	}

	$activities->activities	 = array_values( $activities->activities );

	return $has_activities;
}