Authorities say it's one of the most difficult-to-detect financial crimes. Gas skimmers on pumps grabbing your credit card info.
In fact, there have been around 50 of the devices found at Valley gas stations this year. Authorities say sometimes you can tell if a pump has been tampered with. The Department of Weights and Measures sticker may be torn.
"I usually do check to see if it looks natural if it's part of the machine or if it's something that's unnatural there," David Brown of Phoenix said.
But now, there's another way to check. It's through your phone with an app called Skimmer Scanner.
To use it, you hold your phone up near the pump before you get your gas. Press scan. The app then looks for all of the bluetooth-based skimmers in the area. It will then tell you if it detects one. In that case - you should tell the gas station attendant immediately. The app won't detect it if the skimmer doesn't use bluetooth technology.
Currently, it's free for Android phones on the Google Play store. It's not available on Apple devices.