Privacy Policy

1. Information We Collect

The Dang Bai Tu Dong extension collects the following information in order to provide its services:

• Facebook User ID and display name — to identify you within the system and display your identity on the dashboard.
• Facebook group list (group name, group ID, member role) — to display, manage, and schedule posts to your groups.
• Facebook login session (cookie) — to perform actions on Facebook on your behalf. This data is stored locally only on your device.
• Email address — when you register an account on dangbaitudong.vn.

We do not collect: your Facebook password, private message content, personal friend lists, or financial data.

2. How We Use Your Data

Collected data is used for the following purposes:

• Service delivery: Posting, reposting, group management, and automated post scheduling.
• Authentication: Verifying your access rights and subscription plan.
• Group classification: Group names may be sent to an AI API (Anthropic Claude) for automatic categorization. Only the group name is transmitted — no personal information is included.
• Product improvement: Anonymous usage statistics (post count, group count) to enhance the user experience.

3. Data Storage

• Local data (on your device): Facebook cookies, extension configuration, and recent activity history — stored via the Chrome Storage API. Uninstalling the extension permanently deletes all local data.
• Server data: Email address, Facebook UID, display name, group list, and post history — stored in a PostgreSQL database hosted in Vietnam.
• Retention period: Data is retained for as long as you use the service. Upon account deletion, all data will be removed within 30 days.

4. Data Security

• Facebook cookies are stored locally only on your device and are never transmitted to our servers.
• Communication between the extension and our servers is authenticated using HMAC-SHA256 (bridge authentication).
• All connections use HTTPS (TLS 1.2+).
• Account passwords are hashed with bcrypt before storage.

5. Third-Party Data Sharing

We do not sell, rent, or share personal information with any third party, except as follows:

• Anthropic (Claude AI): Facebook group names (without personal information) may be sent for automatic classification. See Anthropic's privacy policy.
• Legal requirements: When required by a competent authority under applicable Vietnamese law.

6. Your Rights

• Data access: You can view all your data on the dashboard.
• Delete local data: Uninstalling the extension permanently removes all data stored on your device.
• Account deletion: Contact support@dangbaitudong.vn to request deletion of your account and all server-side data.
• Data export: You can export your group list and activity history from the dashboard.
• Revoke access: You may revoke the extension's access at any time by uninstalling it.

7. Cookies and Tracking

The website dangbaitudong.vn uses session cookies necessary to maintain your login state, plus analytics cookies (Google Analytics) and an attribution cookie (stored up to 90 days) to improve the product and measure marketing performance. We do not sell your personal data to any third party.

8. Extension Permissions

The extension requests the following permissions and their justifications:

• storage: Store extension configuration and local session data.
• cookies: Read Facebook cookies to perform posting actions (stored locally only).
• scripting, activeTab: Inject scripts into Facebook pages to execute automated actions.
• tabs: Open and manage Facebook tabs during posting.
• alarms: Schedule automated post publishing.
• host_permissions (facebook.com): Access Facebook pages to perform posting and group scanning.

9. Changes to This Policy

We may update this policy from time to time. Any changes will be published on this page with a revised "last updated" date. For significant changes, we will notify you via email or through the extension.

10. Contact

If you have questions about this Privacy Policy, please contact: support@dangbaitudong.vn

Appendix A. UID-to-phone lookup tool and reference data

Source and nature of the data. The lookup tool at /en/tools/check-uid-phone/ and the bulk lookup feature in the web app cross-reference Facebook UIDs against a UID-to-phone mapping dataset that has been publicly circulated since 2019, filtered and normalized for the Vietnamese market. We do not collect new data, do not access anyone's Facebook account, and do not refresh this dataset from Facebook.

Results are for reference only. A returned phone number may have changed hands, be out of service, or be inaccurate at the time of lookup. We make no guarantee as to hit rate, accuracy, or freshness. A result is not legal identity verification and does not replace your own verification with the person concerned.

Your responsibilities. Use the tool only to verify contact details you already have a lawful basis to process — for example a customer who placed an order, or a candidate who submitted an application and was told that verification takes place. Do not use it to build marketing lists, to call or message people without consent, or for tracking, harassment, fraud, or any unlawful purpose. You are responsible for complying with Vietnam's Cybersecurity Law, Decree 13/2023/ND-CP on personal data protection, the Personal Data Protection Law, and any other law that applies to you.

Abuse controls. Lookups are rate-limited per plan and per IP address; lookups from signed-in accounts may be logged to detect abuse. We may suspend or terminate access to the tool when we detect a violation.

Data subject rights. If you want the phone number associated with your own UID to stop being returned, email support@dangbaitudong.vn with the UID and proof that the account is yours. We process such requests within 30 days.

This appendix states how we operate the service. It is not legal advice for your specific situation.