How can a marketplace detect fake accounts without adding CAPTCHAs?

A marketplace can use Maskbreak to assess live network and browser signals before an account publishes listings, contacts sellers or claims a promotion, without requiring a CAPTCHA. Maskbreak returns an allow, review or block recommendation. Your backend must enforce it alongside account permissions and marketplace rules. Suspicious signals help choose what to verify; they do not establish that a person or account is fake.

This Maskbreak-authored guide focuses on account abuse and protecting marketplace actions. The examples are proposed policies, not reported customer outcomes. Documentation and pricing were checked on 11 September 2026.

What does a fake account actually do to your marketplace?

Start with the behavior you need to prevent. A seller may create replacement accounts after moderation, a buyer may send unsolicited messages, or a referral participant may register repeatedly for rewards. Those require different controls. Counting registrations alone misses the point at which an account causes harm.

Write an enforceable rule for each benefit: a suspended seller cannot publish through another account; a referral reward requires an eligible transaction; a new member cannot message an unlimited number of sellers. Your application owns those rules. A fraud API cannot infer your promotion terms or decide whether a listing is truthful.

Where should you check a marketplace account?

Place the check before the server releases the relevant benefit. Checking only the signup screen leaves later publishing or messaging endpoints exposed. The following is an example policy for a second-hand camera marketplace, not a built-in Maskbreak workflow.

Enforce eligibility and record redemption together so simultaneous submissions cannot claim the same benefit twice. OWASP's business-logic guidance covers server-owned state, repeated workflow steps and race conditions. These controls remain necessary even for an ordinary-looking visitor.

What evidence can help identify repeat account abuse?

Follow the integration guide to collect the network token and device fingerprintEventId at the real form, then forward both to your backend. It calls POST /v1/evaluate using MASKBREAK_API_KEY from server-side secret storage. Never expose that key in browser code.

Live results describe VPN, proxy, Tor and cloud-server signals, plus available automation, fake-browser and device-tampering evidence. The VPN or proxy service is named when known. A bare-IP lookup currently checks Tor exits and cloud-server ranges in production; it does not replace live collection.

Optional accountId can support linked-account counts within your own customer scope. Supply an identifier validated by your server, not an arbitrary browser field. Linking uses hashed account identifiers and does not connect identities across Maskbreak customers. Shared devices and household connections need context; neither an account count nor a shared IP proves abuse.

How do you handle review without adding a CAPTCHA?

A VPN alone produces review under Maskbreak's base policy. Customer rules and exceptions can change the final recommendation, so route on decision. Do not substitute the legacy isSuspicious flag or interpret risk_score as a probability of fraud.

For a reviewed listing, hold publication and offer an appropriate path: existing MFA, verified email ownership or a moderator decision. Email ownership alone does not prove seller legitimacy. Bind verification to the account and pending action, check completion on your server, enforce expiry and prevent reuse. A browser-supplied “passed” value, dismissed dialog or successful redirect cannot release the hold. OWASP's transaction-authorization guidance explains why authorization and workflow order belong on the server.

Suppose a seller using a VPN submits a camera listing. Your application saves the draft, verifies the required account check, then rechecks publishing permissions before making it public. If another submission arrives during review, it must not create a second listing. This preserves a recovery path without treating the VPN as proof of dishonesty.

What should happen on block or missing evidence?

A valid block recommendation refuses the protected action. Give a clear explanation and support route without revealing detailed evasion clues. An allow can continue through your existing controls only when the evidence required by your policy is present and valid.

Sending a device event does not guarantee that device evidence resolves. Missing fields, degraded results, timeouts and API errors need an explicit unavailable state. For this example, hold publication or rewards until verification can complete. Test, sample and sandbox responses must never authorize real actions.

Would a CAPTCHA or identity check solve the same problem?

A bot challenge is an optional additional control. If you choose Turnstile, its official validation guide requires server-side Siteverify; tokens are single-use and expire after five minutes. Check the expected hostname and action. A completed challenge does not establish referral eligibility or clear a separate block decision.

Account-abuse screening also does not establish legal identity, card ownership or payment authorization. Keep payment-provider controls, any required KYC checks and chargeback handling separate. An allowed visit is not a guarantee about a seller, payment or eventual dispute.

How can you prove the marketplace action is protected?

• In staging, exercise allow, review, block and unavailable responses with harmless test actions.
• Confirm direct endpoint requests cannot skip the gate or forge review completion.
• Try simultaneous submissions and expired approvals; verify no duplicate listing or reward appears.
• Use your own live browser on the deployed form. Confirm both evidence fields reach the backend, then correlate the evaluation with the action's actual outcome.

A dashboard event alone does not prove enforcement. Review legitimate users' difficulties as well as abuse attempts. Keep evidence private, limit logging and review your privacy disclosures and retention needs.

What does it cost to start?

Maskbreak is free during open beta, with 1,000 visitor checks per hour and no card. Evaluation and authenticated IP lookup share the key's hourly allowance. Count checks across protected actions, retain your own rate limits, and handle HTTP 429 as unavailable verification rather than permission to publish.