The Yelp of Fraud: How Criminals Use Customer Reviews to Sell Synthetic Identities

The Yelp of Fraud: How Criminals Use Customer Reviews to Sell Synthetic Identities

By David Maimon, Head of Fraud Insights, SentiLink

In the digital underground, trust is currency—even among criminals. On Telegram and Facebook, fraud vendors who sell fake and stolen Social Security numbers (commonly known as CPNs, or Credit Privacy Numbers), which are used to build synthetic identities, rely on customer reviews to promote their services. Much like Yelp or Amazon, these fraudsters depend on positive testimonials to build credibility and reassure would-be buyers that their tools “work.” But do they?

To find out, I used Open Source Intelligence (OSINT) and data from SentiLink to analyze three self-identified “satisfied customers” who publicly vouched for CPN vendors in Facebook groups. These weren’t anonymous accounts; each individual had enough digital breadcrumbs to allow deeper investigation. My goal: verify whether the CPNs being advertised were truly used to open accounts, rent apartments, or secure services, and how successful those attempts were.

Take “J,” a 23-year-old from Dallas. He posted on Facebook in September 2024, celebrating a new apartment and crediting a vendor for helping him get a CPN. His social media profile was public and active, making it easy to track him. SentiLink’s data shows that a synthetic identity tied to J was used to apply for utilities at that apartment, and had previously been used for apartment and furniture rentals going back to late 2023. J kept this fake identity compartmentalized—he used a different email and phone number than his real profile, suggesting operational discipline. 

Then there’s “F,” a 26-year-old in Charlotte, North Carolina, who publicly thanked a vendor after securing a rental. Her CPN first appeared in credit applications in May 2024 and was used again in March 2025. But unlike J, F sometimes used her real phone number in tandem with her synthetic identity, creating traceable links between her real and fake profiles. This mix of caution and carelessness illustrates the varied sophistication among CPN users.

Lastly, “M,” a 44-year-old woman in Las Vegas, publicly praised a vendor after using a CPN to rent an apartment she’d previously been rejected from. Internal data confirms that a CPN linked to her was used for credit-building services, and later to apply with a financial institution. Like J, she separated her synthetic and real activity through distinct contact information—a tactic common among more experienced fraudsters.

This investigation reveals that many CPN reviews, in fact, reflect real-world outcomes. These identities are being used—and often successfully—to access housing, utilities, and even credit products. However, it also exposes a spectrum of risks and operational hygiene issues. Some users take steps to obscure their tracks, while others leave breadcrumbs that could easily lead back to them.

The underground fraud economy may be built on deception, but its trust dynamics mirror the legitimate market in uncanny ways. For fraudsters, reputation matters. And for researchers and institutions trying to combat synthetic identity fraud, these reviews are more than chatter—they’re signals. Studying them reveals not only how the CPN market functions, but how real people navigate it, evolve with it, and sometimes, get away with it.