Dec. 15, 2010 -- Your rent check might be in danger if you mailed it from a drop-off box on a street corner or outside a post office. Some say your identity could be too.
One county near Denver is so worried about a scam called "fishing," where thieves steal people's private information by picking mail from U.S. post office boxes, that they're advising residents to avoid using them in some instances.
The district attorney of Arapahoe County, Colorado advised residents Dec. 10 to not use the drop-off boxes for "anything with personal identifying information included." Instead, residents were told to "drop your mail in the slots provided in the lobby of your post office."
"Once you're an identity theft victim, it's too late," said Casimir Spencer of the Arapahoe County district attorney's office. "Identity theft is a huge issue now, particularly with the way the economy is. People are fishing for your information -- your name, your Social Security number, your address."
Spencer said thieves are "fishing" in a creative way by using sticky mouse traps attached to a long string to pull mail out of the drop-off boxes. Then, they'll use sensitive information like that contained on a check to make counterfeit checks, Spencer said. They might steal credit card information, Social Security numbers or other data.
The U.S. Postal Inspection Service said that the drop-off boxes are perfectly safe.
"Less than two percent of all identity theft cases involve mail theft," U.S. Postal Service Inspector Michael Romano said. "Collection boxes are one of the most secure means to deposit mail."
Romano said that they are not seeing a rise in theft from collection boxes and that the incidents in Denver appear to be isolated.
Still, advocates for those whose identities have been stolen said that the blue drop-off boxes are a danger.
The blue boxes have been in the news lately. Earlier this week in Dallas, a man was sentenced to 15 years in federal prison for stealing mail from post office boxes.
"We recommend not using a blue box on a street corner," Linda Foley, founder of the Identity Theft Resource Center, said. "If they must use a Post Office drop box, use the ones at the Post Office before the last pick-up of the day."
Foley said that during the holiday season, drop-off boxes fill up even more quickly. She said that you shouldn't drop your mail in those boxes if they seem full.
She advises her clients to keep a calendar of when to expect their bills. If a bill is more than three days late, she suggests calling the post office manager to ask if there's been a delay in delivering mail.
Drop-Off Boxes Stolen
Not only is mail being stolen from the drop-off boxes, but the boxes themselves are being stolen, Foley said.
"They move them from street corner to street corner so that the thieves are getting the mail instead of who you're sending it to," Foley said.
In Phoenix, a box was stolen last month and has yet to be found.
"When you think of the number of people that may have access to a piece of mail, it's rather scary," Foley said. "It can be stolen at anywhere along the line."
The U.S. Postal Inspection service doesn't have statistics on how many boxes are stolen or illegally moved each year.
Foley said that people should avoid paying bills by mail altogether and pay them online.
"I am a big fan of online banking because it takes the human element away from the situation and it gives you the ability to check your account on a regualar basis to see if anyone is using your credit card," she said.
ABC Affiliate KMGH in Denver contributed to this report.