Credit bureaus and payment companies are testing ways to use social media -- say, a Facebook Inc. post about a recently purchased Corvette -- to verify a person’s identity and even assess consumer creditworthiness.

Equifax Inc., EBay Inc.’s PayPal and Intuit Inc. have begun trials to see whether social posts can help prove identities, and, in some cases, detect whether customers are lying about their finances.

Users of Facebook, Pinterest Inc. and Twitter Inc. share personal details every day through public postings, status updates and location check-ins. That information is proving useful in validating identity, evaluating whether to make a loan and sniffing out fraud that cost U.S. online retailers $3.5 billion last year, according to CyberSource Corp. EBay set aside $580 million, or 4.1 percent of net revenue, to cover transaction and loan losses last year.

“We are investing a lot in how can we use unstructured data that is sitting out there in social media that can help us understand a little more about identity,” Rajib Roy, president of Equifax Identity and Fraud Solutions, said in an interview.

While the companies can only access public information or what people choose to share, a great deal is readily accessible. Many young people allow the public to see certain parts of their Facebook profiles, as well as accounts on Twitter and LinkedIn Corp. Consumers also leave traces of themselves on blog posts, Yelp Inc. reviews and online forums.

Tapping Data

Public data can include photo tags, local check-ins, and a person’s network of friends on Facebook. Credit bureaus such as Equifax and Experian Plc, and payment-processing companies such as Intuit, Braintree Payment Solutions LLC and WePay Inc., are all in the early stages of using social media more often to verify that merchants and consumers are who they claim to be.

As Internet purchases rise -- U.S. e-commerce revenue increased 15 percent in the first quarter from a year earlier, according to the U.S. Department of Commerce -- more would-be thieves are trying to find ways to intercept transactions facilitated by online payment providers, steal information transmitted in the process, or dupe buyers into sending money to phony companies.

Social media has helped detect red flags. If a business claims to be a hairdresser in Pittsburgh, for example, WePay can match the phone number from its application to the one listed on Yelp, see consumer reviews, and check that the business’s e-mail matches the one it uses on its Twitter account. WePay can also look at the length of time the business has had a presence on Yelp, Twitter and Facebook to verify its legitimacy.

Privacy Concerns