Using stolen names and Social Security numbers, criminals file fake electronic tax forms to claim refunds, exploiting a slow-moving federal bureaucracy to collect the money before the victims or the IRS discover the fraud, the article reports. The IRS says that it has detected cases in every state except for North Dakota and West Virginia, and the fraud’s epicenter is in Florida.

Miami has 46 times the per-capita rate of false tax refund claims than the rest of the country, and 70 times the national average in dollar terms, Reuters reports. The higher rate can be partly explained by the high proportion of older residents, who can be more vulnerable to fraud.

But nationally, the number of tax identity theft is skyrocketing – 2012 brought 1.2 million cases; 2008 had only 48,000.

One of the main issues with this fraud is its link with armed gangs. Fraudsters are drawn by the ease of the crime, officials say. All they need is a name and a tax ID number. Other details on the form – addresses, employer data, income and deductions – can be made up, Reuters writes.

The IRS has doubled the number of agents (now at 3,000) working on the problem. But despite the increase in investigations, the agency reports it has a backlog of 300,000 people waiting for legitimate refunds after they were fraud victims. It takes an average of six months to resolve a case, Reuters reports.