Last week, the Internal Revenue Service announced that it had targeted about 400 identity thieves across the country. The thieves were using stolen Social Security numbers to file false tax returns and then claim the refunds.

The full crackdown, which began in January, has yielded 189 indictments and more than 100 arrests. Tax-related identity fraud has become a larger and larger problem as electronic filing has grown, making it easier for criminals to submit batches of false returns and to receive refund dollars. The IRS says there were 5 million suspicious returns filed in 2012, compared with 3 million in 2011.

The map above shows where the IRS's January enforcement actions took place. Fifteen states received no attention, while the agency focused heavily on about 17 metropolitan areas.

The IRS has also set up a "Taxpayer Guide to Identity Theft" on its website. It gives a simple rundown of what identity theft is, how you can find out if you have been victimized, what to do if you have been targeted, and how to protect yourself against it. Some of its recommendations for preventing tax-refund fraud from happening to you include:

  • Don’t carry your Social Security card or any document(s) with your SSN on it.
  • Don’t give a business your SSN just because they ask. Give it only when required.
  • Protect your financial information.
  • Check your credit report every 12 months.
  • Secure personal information in your home.
  • Protect your personal computers by using firewalls, anti-spam/virus software, update security patches, and change passwords for Internet accounts.
  • Don’t give personal information over the phone, through the mail or on the Internet unless you have initiated the contact or you are sure you know who you are dealing with.