How to Protect Your Personal Info on Online Marketplaces

eBay, Facebook Marketplace, Poshmark, Mercari — online marketplaces make buying and selling incredibly convenient. But every transaction involves exchanging personal details: names, addresses, phone numbers, and payment information. When this data falls into the wrong hands, it can lead to stalking, fraud, and identity theft.

Personal Info You're Exposing in Every Transaction

Info Type	When It's Exposed	Risk
Full name	Payment transfers, shipping labels	Identity verification, social engineering
Phone number	Direct communication	Spam, phishing, stalking
Home address	Shipping, local meetups	Stalking, physical threats
Bank details	Payment requests	Financial fraud
Photos	Profile pics, product photo reflections	Identification

Securing Your Profile

Use a Username, Not Your Real Name

Don't put your full name in your marketplace profile. A username is sufficient for transactions and protects your identity.

Be Careful With Profile Photos

Use an avatar or object photo instead of your face. Check that your product photos don't accidentally capture reflections of yourself or identifiable surroundings.

Don't Trust Ratings Blindly

High seller ratings don't guarantee safety. Scammers can build up positive reviews before executing larger scams. Always follow security fundamentals.

7 Rules for Protecting Personal Info During Transactions

1. Don't Share Personal Details Directly in Chat

Never type your bank account number, address, or phone number directly into a marketplace chat. Use LOCK.PUB to create a password-protected memo with this information. Set an expiration time so the data disappears after the transaction.

2. Use Platform Payment Systems

PayPal Goods & Services, eBay Managed Payments, and Facebook Pay keep your financial details hidden from the other party.

3. Use In-App Messaging Instead of Personal Contact

Avoid sharing your personal phone number or email. Keep communications within the platform's messaging system for accountability and safety.

4. Choose Meetup Locations Carefully

For local sales, meet in public places — coffee shops, police station parking lots, or busy shopping centers. Never invite strangers to your home.

5. Minimize Info on Shipping Labels

Use a PO box or business address instead of your home address. Services like Pirate Ship or platform-integrated shipping can help mask personal details.

6. Scrub Photos Before Posting

Check product photos for identifying information: mail with your address, reflections showing your face, license plates in the background, or visible WiFi network names.

7. Clean Up After Transactions

Delete conversations containing personal details after the transaction is complete. Don't leave sensitive information sitting in old chats.

Common Marketplace Scams to Watch For

Typical Scam Tactics

• Overpayment scam: Buyer "accidentally" pays too much, asks for refund of the difference
• Fake payment confirmation: Screenshots of fake payment receipts
• Off-platform payment requests: "Pay through this link instead" → phishing site
• Info harvesting: Asking for excessive personal details beyond what's needed

Red Flags

• Prices significantly below market value
• Pressure to move communication off-platform
• Rushing to close the deal
• Insisting on unusual payment methods

If Your Personal Info Has Already Been Exposed

1. Block and report the suspicious buyer/seller
2. Change passwords and monitor accounts related to exposed info
3. If you feel physically threatened, contact local police
4. Place a fraud alert on your credit reports
5. Consider an identity monitoring service temporarily

Build Safer Sharing Habits

When you need to share an address or bank details for a marketplace transaction, don't paste them into the chat. Use LOCK.PUB to create a password-protected, self-expiring memo and share only the link. Once the buyer or seller has accessed the info, it's gone — not sitting in a chat log forever.

The Bottom Line

Online marketplaces are convenient, but remember: you're exchanging personal information with strangers. Make the security practices above a habit, and use tools like LOCK.PUB to minimize unnecessary exposure of your personal data. A little caution goes a long way in preventing serious problems.