The Alpharetta-based company said it has hired a retired Secret Service agent to help revamp its verification process. It also has paid for a one-year subscription to a credit monitoring service for each of the 144,778 people that may have been affected by the breach.
The company said the smallest number of possible victims - two - was in the U.S. Virgin Islands, while the largest number - 34,114 - was in California. It released a state-by-state breakdown late Monday. People in Puerto Rico and Guam also may have been affected.
There were 1,730 possible victims in Arizona.
Formed in 1997 as a spinoff of credit reporting agency Equifax Inc., ChoicePoint has 19 billion public records in its database at its suburban Atlanta headquarters, including motor vehicle registrations, license and deed transfers, military records, names, addresses and Social Security numbers.
Wall Street was closed for the Presidents Day holiday on Monday, but on Friday, ChoicePoint shares slipped 63 cents to close at $43.50 in heavy trading on the New York Stock Exchange - down from nearly $48 a share on Feb. 4.
Taser International Inc., the Scottsdale-based maker of stun guns, announced last month that it had chosen ChoicePoint to conduct criminal background checks and verify the identity of private citizens trying to buy its stun guns.
ChoicePoint said it is almost done notifying by mail all of the potential victims. California authorities have said as many as 500,000 people may have been affected, but ChoicePoint disputes that number.
"All I can tell you is our number is roughly 145,000, and we know that we're over-notifying," ChoicePoint marketing director James Lee said. "There will be duplications in there."
Last week, attorneys general in 38 states demanded ChoicePoint inform all affected consumers that they might vulnerable to identity theft amid concerns the company was foot-dragging. Politicians have also become involved, with two U.S. senators calling for hearings and stepped-up regulations to protect consumers.
As for the rescreening, ChoicePoint said any business that is not publicly traded or not a government agency will have to be recredentialed to use its services.
"It will involve the revalidation of any information they previously provided as well as requests for additional information," Lee said. "Certain customers will receive site visits, but I can't be more specific than that because we don't want to reveal too much."
He said it could take up to 60 days to recredential the affected customers.
Once recredentialed, those customers will no longer receive access to consumers' Social Security numbers, dates of birth and driver's license numbers unless they are sponsored by a public company or government agency, Lee said.
The company said in a statement that it is seeking to "remove information in those segments where organized crime fraud is likely to occur."
The customers affected represent less than 5 percent of the company's $900 million in annual revenue.
The company acknowledged last week that thieves apparently used previously stolen identities to create what appeared to be legitimate businesses seeking ChoicePoint accounts. The bandits then opened up 50 accounts and received volumes of data on consumers, including names, addresses, Social Security numbers and credit reports.
The ring, which operated for more than a year before it was detected, used the information to defraud at least 750 people, according to investigators in California.
Like any business that opens an account with ChoicePoint, the suspect companies were given an access code and password that allowed them to use ChoicePoint's database. ChoicePoint says it puts applicants for accounts through rigorous protocols such as verifying business licenses and individual's names and background checks.
In this case, the thieves - posing as check-cashing companies or debt collection firms - provided business licenses that appeared to be legitimate and used the names of real people with clean criminal records.
The company caught on later by tracking the pattern of the searches conducted by the suspects.
The company learned of the problem in October, but did not notify those customers who were possibly affected until this month because authorities did not want to jeopardize their investigation.
By Harry R. Weber