private void removeOrphanedPlatforms(AuthzSubject overlord) {
   final Collection<Platform> platforms = platformManager.getOrphanedPlatforms();
   if (!platforms.isEmpty()) {
     log.info("cleaning up " + platforms.size() + " orphaned platforms");
   }
   for (Platform platform : platforms) {
     try {
       platform = platformManager.getPlatformById(platform.getId());
       platformManager.removePlatform(overlord, platform);
     } catch (ObjectNotFoundException e) {
       log.warn(e);
       log.debug(e, e);
     } catch (PlatformNotFoundException e) {
       log.warn(e);
       log.debug(e, e);
     } catch (PermissionException e) {
       log.warn(e);
       log.debug(e, e);
     } catch (VetoException e) {
       log.warn(e);
       log.debug(e, e);
     }
   }
 }