Today, there are over 2.2 million ATMs worldwide, and by 2015 there will be around 3 million. ATM skimming accounts for as much as 30% of all data theft. That’s about $350,000 in fraud every day in the United States alone, or more than a billion dollars a year.

The ATM Industry Association is now attempting to address the security threat posed by decommissioned ATMs, urging ATM deployers to exercise more caution when discarding old machines.

This is partially in response to recent media reports about criminals who hunt for discarded ATMs in junkyards. Old ATMs sometimes contain stored card data. Criminals can study a discarded ATM’s security features in order to improve their own skimming techniques. The faces of old ATMs can also be used to mold plastic covers for skimming devices.

In some cases, used ATMs are purchased on eBay or Craigslist, then installed anywhere with ample foot traffic. These machines, which may be powered by car batteries or simply plugged into the nearest outlet, are programmed to read and copy credit card data. I was able to find a used ATM on Craigslist, which I bought from a guy at a bar for $750.

Protect yourself from ATM skimming by checking your credit and debit card statements online at least once every two weeks, and refuting any unauthorized transactions within 30 or 60 days.

When using an ATM, pay close attention to the appearance and behavior of the machine. Look for red flags like wires, tape, unusual features, or anything that seems out of place. Try to avoid using generic ATMs in less secure locations. Whenever possible, choose an ATM at a more trustworthy and secure location, but do not drop your guard simply because an ATM is located in a bank. And when entering your PIN, use your other hand to cover the keypad.

McAfee Identity Protection includes proactive identity surveillance to monitor subscribers’ credit and personal information and access to live fraud resolution agents who can help subscribers work through the process of resolving identity theft issues. For additional tips, please visit http://www.counteridentitytheft.com

Robert Siciliano is a McAfee consultant and identity theft expert. See him discuss ATM skimming on Fox Boston. (Disclosures)