The personal information gathered by companies such as Little Rock-based Acxiom Corp. to classify people for targeted marketing campaigns is also useful for creating profiles of terror suspects and helping investigators find accomplices, industry members say.
Information held in technology company databases would have been useful to the investigators scouring neighborhoods in France and Belgium last week in search of suspects involved in the Paris terrorist attacks.
"In situations like this, governments and proper authorities need to have access to more data because the key to finding these guys is the data," said Charles Morgan, former chief executive for Acxiom.
It is unknown whether any tech and data companies are assisting intelligence agencies with their investigations of the Paris attacks. Acxiom, which has operations in Europe and an office in Paris, declined to comment for this story.
Acxiom assisted the FBI in gathering information about the 19 hijackers involved in the Sept. 11, 2001, terrorist attacks.
Most people leave a data footprint, a fact that attracts law enforcement and intelligence agencies to Acxiom and other tech companies.
The data trails vary. The data can come from bank accounts, rental or home addresses, travel patterns, phone records, online activity and even purchasing history. Data-mining companies collect similar information on millions of people and sell the data to clients such as retailers, which use it for targeted marketing campaigns.
Combining behavioral information with biographic information -- such as names, addresses and fingerprints -- can help identify both a person involved in an attack and potential links he has to terrorist organizations, experts say.
Despite the huge amount of data that Acxiom and other companies collect each year, the depth and amount of information they might be able to provide authorities in France and Belgium is limited because they have stricter privacy laws than the United States, Morgan said.
A debate focused on the need for law enforcement and intelligence agencies to have access to data and on the competing need to protect the privacy of individuals has been ongoing since the Sept. 11 attacks. The discussion has leaned more toward protecting privacy in recent years, especially in light of recent disclosures regarding government spying.