Last month, Clark took a call on the show from a man who worked at a gas station. The man alleged that there are certain standard keys that open numerous gas pumps across brands. At the time, Clark just filed the info in the back of his brain and didn't know what to think of it...until he saw an article about a gas pump skimmer scam that was recently busted.

The San Francisco Chronicle reports a criminal ring that targeted Arco and 7-Eleven gas stations in the San Francisco area was brought down when authorities did a gas station stake-out. The ring's m.o. included using the master keys to open gas pumps and insert skimmers that captured debit card numbers and PIN info.

So our caller was right!

Unfortunately, there's no way for customers to detect this scam because the skimmers are completely invisible to the naked eye when they're in the pump. The California ring was only brought down because a gas station employee noticed something wasn't right during a routine maintenance check.

The moral of the story? Never buy gas at the pump with a debit card. Always pay cash or with a credit card. You're afforded more protections with a credit card (versus a debit card) and you're completely immune from being scammed when you pay cash.

Meanwhile, Clark recently told you about a resurgence of skimmer devices being put on ATMs. Brush up on his method for detecting ATM skimmers.

For more information:
Would this ATM skimmer Have Fooled You? (article)
An illustrated guide on how to detect ATM skimmers. (PDF)