Federal authorities arrested nearly 50 people in connection with an ATM scam targeting thousands of victims in Southern California.

On Nov. 23, Romanian law enforcement collaborated with the FBI’s L.A. office focusing on 84 locations throughout Romania. The locations were tied to an organized crime group known for ATM skimming and money laundering, authorities said.

During the massive bust, 48 people were arrested and around $1 million in cash and cryptocurrency, along with 11 vehicles, were seized.

Over 8,000 stolen credit card numbers belonging to U.S. citizens were recovered during the operation. 

Many of the arrested suspects worked directly or were associated with Florian Tudor, the alleged leader of the “notorious and violent ATM skimming organization known as the Riviera Maya Gang based out of Cancun, Mexico,” said the FBI.

The suspects would steal funds through ATM skimming devices and send the money through Western Europe before it arrived in Romania.

“Skimming” involves a suspect installing devices on ATMs and point-of-sale terminals to record cardholders’ personal identification numbers (PINs) and create fake debit or credit cards to steal from victims’ accounts.

The major bust was the result of a three-year investigation by FBI and Romanian authorities. Photos from the arrests show a large amount of ATM skimming devices, technology and cards used in the large-scale theft.

The suspects arrested have been charged with conspiracy, bank fraud, aggravated identity theft, and visa fraud.

Tudor is currently awaiting trial in Mexico on fraud charges and is facing charges of attempted murder in Romania.

Card skimmers can be hard to detect because they are designed to blend into the terminal, L.A. County officials warn.

Some ways to protect yourself against skimming thefts include:

• Keep your PIN and EBT account numbers a secret
• Cover your hand when entering your PIN
• Self-inspect ATMs and point-of-sale machines for illegally installed devices. Does it wiggle, seem loose or tampered with? If so, do not swipe or insert your card and notify the business and local law enforcement
• Use contactless-enabled cards or phones for safe payments by tapping your card or phone on a contactless-enabled payment terminal
• For EBT users, the County or State will never call or text to request your EBT card number or PIN. Do not click on any links from text messages or emails regarding your EBT card
• Watch out for suspicious websites
• Sign up for notifications or alerts for your bank and credit card transactions to receive a notification or alert whenever your card is used
• Make sure to check your receipt after each purchase

If your credit or debit card has been skimmed, contact local law enforcement immediately to file a report. Call to report any suspicious activity or unauthorized charges to your card issuer, as well.

To learn more about ATM skimming and ways to identify skimming devices, visit L.A. County’s website.