Ace Cash Express is principally a payday-loan provider, but its Facebook ads earlier this year sought customers for longer-term loans. Ace's site had a message telling California borrowers that "ACE no longer offers installment loans. Apply for a payday loan up to $255."

A representative of Populus Financial Group Inc., which does business as Ace Cash Express, didn't respond to requests for comment.

High-cost lenders also buy data on Facebook users who have been identified as people in financial distress from third-party companies that compile the information without Facebook's involvement. Chicago-based Exact Data sells marketing lists titled "People Struggling With Bills" and "Get Me Out of Debt!" that purport to offer millions of Facebook addresses for struggling consumers. The price is as little as $249 for more than 10 million names.

The Facebook information can be used for "prospecting effectively by laser targeting [the] audience," said Larry Organ, founder and chief executive of Exact Data.

Write to Coulter Jones at Coulter.Jones@wsj.com, Jean Eaglesham at jean.eaglesham@wsj.com and AnnaMaria Andriotis at annamaria.andriotis@wsj.com