-- When it comes to stealing credit card information, it's unfortunately as easy as swiping your card in any skimming device.
Credit card fraud is now a $16 billion a year problem in the United States alone, and every hour, thieves with skimmers are stealing Americans' credit card numbers.
"When the magnetic stripe was created, identity theft wasn't an issue. And so the data was never properly encrypted," Robert Siciliano, a cyber-crime expert, told ABC News' "Nightline."
Credit card thieves can use a skimming device to swipe data through credit cards' magnetic strips.
"[Thieves] can use those 16 digits over the phone to place a phone order. They can use them online to plug it into a website, or they can actually clone a card. They can burn the information onto a blank ATM or credit card and use that out in the wild," said Siciliano.
The latest weapon in the U.S. to fight against credit card crime is the newly issued chip technology and signature card, which is supposed to eliminate the cloning of your credit card. You may have recently received a new card with a chip, which holds your encrypted data, from your bank.
But even with the added protection of a chip, Siciliano says credit card fraud is still possible.
"Skimming is still alive and well, and it will continue to be alive and well as long as that magnetic stripe is still on the back of our cards," Siciliano said.
Because it's taking a lot of time and money for businesses to make the switch, most cards now have a chip and a magnetic strip that still contains personal data on it, making you still susceptible to thieves with skimmers.
"[Thieves] could easily have what's called a wedge-type device, a small skimming device. They could grab all the information off of it and they could actually create a whole other credit card, so watch them closely," Siciliano said.
With that magnetic strip still in place on cards with chips, the ATM could even be a potential danger.
"Be aware that at any given point in time there could be a skimming device on that ATM," Siciliano warned. "Make sure to cover up the keypad with your other hand as you're punching your pin code, because there could be a camera anywhere recording your pin number.
Thieves can even use a phone app to steal credit card details by placing the phone on another person's wallet for just a few seconds. And as cards with chips catch on, thieves will move increasingly to so-called "card not present" transactions where the chip means nothing, such as with online shopping.
To protect yourself from credit card thieves, you can use a wallet that blocks scanning devices or the Signal Vault, which looks like a credit card but has the same blocking powers as a shielded wallet.
Siciliano also says to beware of making purchases on public WiFi.
"The problem with free WiFi is that it is unencrypted and unprotected. Make sure you have a VPN, a virtual private network, that encrypts and locks down your information on free public WiFi," he said.
It also helps to make your passwords complex, to check your statements for suspicious activity to know if you've been skimmed, and to sign up for alerts that notify you every time your card is used.
However, Siciliano says that no one has yet seen thieves be able to hack credit cards with just chips.
"Researchers in a controlled environment have been able to get information off of chip cards. Whereas, out in the wild, criminal hackers haven't actually been able to crack the code as far as we know," Siciliano said.