For ATM manufacturers this detector may end up being helpful. If all ATMs start returning a reading of 15 or higher, then skimmers won't be fitted. But as Charlie Harrow, solutions manager for ATM maker NCR Corp., pointed out to Krebs, anti-skimming tech isn't usually hidden. Manufacturers want the skimming thieves to know a machine is well-protected and not worth their time. That way, they leave it alone.