public function mark_as_spam( $activity, $source ) {
		// Record this item so we can do some tidyup in BP_Akismet::check_member_activity_update().
		$this->last_activity = $activity;

		/**
		 * Fires after marking an activity item has been marked as spam.
		 *
		 * @since 1.6.0
		 *
		 * @param BP_Activity_Activity $activity Activity object being marked as spam.
		 * @param string               $source   Source of the whom marked as spam.
		 *                                       Either "by_a_person" (e.g. a person has
		 *                                       manually marked the activity as spam)
		 *                                       or "by_akismet".
		 */
		do_action( 'bp_activity_akismet_mark_as_spam', $activity, $source );
	}