Peer-to-Peer, Public by Default: The Privacy Gaps Hidden Inside America's Favorite Payment Apps
America's peer-to-peer payment market processed an estimated $1 trillion in transactions in 2023. Venmo, Cash App, Zelle, and Apple Pay Cash have become the default infrastructure for splitting dinner bills, paying rent to roommates, reimbursing friends, and settling small debts of every variety. The convenience is genuine. The privacy implications, however, are considerably less discussed — and in several cases, actively concealed by default settings that favor data collection over user protection.
CipherWatch reviewed the privacy policies, default configurations, and documented exploitation patterns across the four most widely used peer-to-peer payment platforms in the United States. What follows is an honest accounting of what these services know, who they share it with, and where the risks concentrate.
The Public Feed Problem
Venmo's most distinctive — and most problematic — feature is its social transaction feed. By default, every payment a user sends or receives is visible to that user's contacts within the app, and the transaction note (the emoji-laden description of what the payment was for) is visible to the general public. This is not a bug. It was an intentional design decision rooted in the app's early positioning as a "social" payment experience.
The consequences of this architecture have been documented repeatedly by researchers. In 2021, privacy advocates demonstrated that Venmo's public API allowed automated scraping of transaction data at scale. Buzzfeed News journalists were able to identify President Biden's Venmo account and map his social connections within minutes using only the public feed. A separate research project scraped over 200 million Venmo transactions over a six-month period, extracting social graphs, behavioral patterns, and in some cases sensitive personal details inadvertently included in transaction notes.
PayPal, which owns Venmo, settled with the Federal Trade Commission in 2022 over privacy-related issues and has since made incremental changes to default settings — but the social feed remains active for users who have not manually adjusted their privacy controls.
What the Apps Know Beyond the Transaction
The payment itself is only one data point. The information P2P platforms collect around each transaction is substantially broader.
Venmo's privacy policy, as of its most recent revision, discloses collection of:
- Device identifiers, IP addresses, and geolocation data
- Contacts list data (if permission is granted)
- Transaction history, including amounts, counterparties, and notes
- Linked bank account and card metadata
- Usage patterns and in-app behavior
Cash App, operated by Block (formerly Square), similarly collects device data, location information, and transaction history. Its privacy policy explicitly states that it may share data with "affiliated companies" and "service providers," a category broad enough to encompass advertising technology partners.
Zelle operates through a consortium of participating banks and does not maintain its own consumer-facing data repository in the same way — but transaction data flows through the Early Warning Services network, a bank-owned consortium, and is subject to each participating institution's own data practices.
For users who have linked government-issued identification for account verification purposes — a requirement triggered by transaction volume thresholds — the platforms hold identity documents, Social Security number fragments, and date of birth data in addition to financial activity records.
How Fraudsters Use Public Data to Target Victims
The public and semi-public nature of P2P transaction data is not merely a privacy inconvenience. It is an active attack surface that criminal actors exploit in documented and recurring ways.
Social engineering via transaction history. A scammer who can observe that a target regularly sends payments to a specific landlord or utility provider can craft highly convincing impersonation messages. "Hi, this is [landlord's name] — I've switched accounts, please send this month's rent to this new Venmo handle" becomes far more credible when the fraudster already knows the target's payment schedule and the landlord's name from the public feed.
Romance and investment scams. Fraudsters who identify targets through Venmo's social graph — mapping who pays whom, and how frequently — can use that information to establish false familiarity before initiating contact through other channels. A target who is known to regularly pay a gym, a yoga studio, and a coffee shop can be approached with a persona calibrated to those interests.
Overpayment fraud. This scheme is well-documented across all P2P platforms. A fraudster sends an "accidental" overpayment and requests a partial refund. The initial payment is funded by a stolen payment method and is subsequently reversed by the victim's bank or the platform — but the refund the victim sent is gone. Because P2P payments are generally processed as instant transfers, chargebacks are not available in the way they would be with a credit card.
Account takeover via credential stuffing. Payment app accounts are high-value targets for credential stuffing attacks, in which usernames and passwords leaked from other data breaches are systematically tested against financial platforms. A successfully compromised Venmo or Cash App account can be drained quickly, with transfers routed to accounts the attacker controls before the victim is aware of the intrusion.
A Comparative Look at Default Privacy Settings
Not all platforms are equally opaque by default. The following reflects each platform's out-of-the-box configuration as of early 2025:
| Platform | Default Transaction Visibility | Data Sharing with Advertisers | Biometric Lock Default |
|---|---|---|---|
| Venmo | Public (note and parties visible) | Yes, via PayPal network | Off |
| Cash App | Private | Yes, via Block affiliates | Off |
| Zelle | Private (bank-to-bank) | Varies by institution | Varies |
| Apple Pay Cash | Private | Limited (Apple's stated policy) | On (Face/Touch ID) |
Apple Pay Cash represents the strongest default posture among major platforms, reflecting Apple's broader positioning on privacy as a product differentiator. Zelle's privacy exposure is largely a function of which bank a user accesses it through. Venmo's public default remains the most significant structural concern for privacy-conscious users.
Hardening Your Payment App Accounts
The following steps represent the minimum recommended configuration for users who regularly transact through P2P platforms.
Set all Venmo transactions to private immediately. Navigate to Settings → Privacy → and set both "Transactions" and "Friends List" to "Only Me" or "Friends" at most. This should be the first action taken upon creating a Venmo account, and it should be verified periodically, as platform updates have been known to reset user preferences.
Enable multi-factor authentication on every payment app. All major P2P platforms support two-factor authentication via SMS or authenticator app. An authenticator app (such as Authy or Google Authenticator) is strongly preferred over SMS, which is vulnerable to SIM-swapping attacks — a threat CipherWatch has covered in depth in prior reporting.
Activate biometric or PIN locks. Ensure your payment app requires authentication to open, not merely to log in. A phone that is unlocked but left unattended should not provide immediate access to your payment history or the ability to initiate transfers.
Use a dedicated email address for financial apps. Compartmentalizing your financial account credentials limits the blast radius if an unrelated data breach exposes your primary email address and password.
Never send money to resolve an "accidental" overpayment. No legitimate transaction requires you to refund a stranger for money they claim to have sent by mistake. Decline the request, report the account to the platform, and do not send any funds until the original payment has fully cleared and been confirmed by your bank — which, in overpayment fraud scenarios, it ultimately will not.
Review linked accounts and authorized apps periodically. Payment platforms accumulate linked bank accounts, cards, and third-party app authorizations over time. Remove any connections you no longer use, and audit the list of apps that have been granted access to your payment account through OAuth integrations.
The Regulatory Picture
In 2023, the Consumer Financial Protection Bureau proposed rules that would extend federal oversight to large P2P payment providers under the Electronic Fund Transfer Act, requiring greater transparency around error resolution, fraud liability, and data practices. The proposal drew significant industry opposition and its implementation timeline remains uncertain. In the interim, users of these platforms have substantially fewer statutory protections than they would using a federally regulated bank account or a credit card covered by the Fair Credit Billing Act.
Closing Assessment
Peer-to-peer payment apps offer genuine utility, and abandoning them entirely is neither practical nor necessary for most users. What is necessary is treating them with the same deliberate security posture applied to any other financial account. The defaults these platforms ship with were not designed with your privacy as the primary consideration. Adjusting them is a five-minute task that meaningfully reduces both your data exposure and your vulnerability to social engineering. In the current threat environment, that is time well spent.
