public function getTargetFilter() {
		$target = $this->getRequest()->getVar('target');
		if ($target) {
			// verify it's a class/ID
			list($targetType, $targetId) = explode(',', $target);
			$targetId = (int) $targetId;
			if (class_exists($targetType) && $targetId > 0) {
				return "$targetType,$targetId";
			}
		}
	}