Tom Mahoney, founder of Merchant911.org, an online forum used by merchants to share fraud prevention information, said he had "mixed feelings about the service, as do a lot of others."

"I have no reason to think the company is anything but honest," Mahoney said. And it most probably is taking the precautions needed to protect its database, he said. "But asking someone to enter their Social Security and credit card numbers on a virtually unknown site is going to be a real tough sell," he said.

He also expressed concern that people might mistakenly conclude they are safe if their names do not appear on TrustedID's site. "The 2.3 million records they have is only a drop in the bucket," compared with the tens of millions of records that have been exposed over the past few years. "I guess StolenID Search is probably a start, but they need to amass a lot more records and be a lot plainer about warning visitors that not being in the database doesn't relate to their numbers being safe."

Mitic acknowledged that the company has seen thousands of comments from people since the service was launched. Most of the negative responses are the result of a "combination of a lack of information and irrational fear in the blog echo chamber," he said.

Contrary to what users might assume, TrustedID saves none of the personal information that goes into the search box at the StolenID site, he said. The company is retaining the first six digits of the credit card numbers being inputted on its site to know which bank issued the card, he said. But the last eight digits, which contain consumer-specific data, are purged immediately after each search. The company also stores the first three digits of the Social Security numbers being entered to know which state the card was issued in but nothing else.