MISSOULA, Mont. (AP) - A new report indicates Montanans and North Dakotans should brace themselves for attempts by would-be thieves to steal their identities.

ID Analytics Inc., a California company that sells fraud-protection products to businesses, says Montana has one of the fastest-rising identity fraud rates in the nation.

The company analyzed fraud reports filed throughout the United States last year to determine which ZIP codes were experiencing the most criminal activity, said Stephen Coggeshall, the report's author and ID Analytics' chief technology officer in San Diego.

The highest instances of such activity were in the nation's biggest cities; but Coggeshall was surprised to find that identity fraud was increasing fastest in the relatively rural states of Montana and North Dakota, he told the Missoulian in a telephone interview.

The newspaper reported the study Thursday.

Overall, six Montana communities made the company's top 10 list of identity fraud "hot spots." Springfield, Ill., leads the list followed by Bozeman and Missoula, Mont., in second and third place, respectively. Whitefish, Lolo, Hamilton and Bigfork, Mont., are also included, with North Dakota's Bismarck, Grand Forks and Fargo rounding out the top 10.

It's likely, Coggeshall said, that the high numbers were caused by an organized ring of identity thieves sweeping through the region.

The nation as a whole is grappling with more cases of identity fraud, said special agent Ron Mosback in Missoula. While his office has not seen a marked increase in the number of identity theft cases, it certainly gets its share of counterfeit checks, fake lotteries and Internet scams, he said.

"I think Montana is targeted because rural communities tend to be more trusting," said Roxanne Roehl, senior vice president of Missoula Federal Credit Union.

Mosback warned consumers against sharing any personal information over the phone or Internet unless the consumer initiates contact.

"You should never give your personal information over the phone if you're not sure who you're talking to," he said.

He also encouraged people to go over their credit histories regularly, perhaps every six months or so, looking for purchases they didn't make.

Public awareness is one of the best defenses against identity theft and other fraud, Mosback said. Once word of a particular scam is out, fewer people fall prey to it and scammers are forced to find a new strategy.