Privacy Policy

Definitions

Participant: A "participant" refers to any app user with an account, regardless of whether they answer any surveys. Participants are governed by this Privacy Policy for all actions within the app, including account creation, data management, and answering surveys.

Study: A "study" refers to a complete research project created by a customer through the Dashboard, consisting of multiple question and/or user feature variations. From the participant perspective, "studies" are presented as individual survey questions that participants may answer with yes/no responses or skip. Anonymized survey responses, along with selected self-inputted user features (e.g., age, gender), are returned to Linesol, processed, aggregated, and included in comprehensive reports delivered to the customer. These reports are provided in PDF format along with accompanying CSV data files. These reports may also be accessible to third parties as listed in this Privacy Policy.

0. Scope

This policy applies exclusively to the Linesol mobile app used by participants for answering surveys. It does not cover the Linesol Dashboard, which is used by business customers to create studies. The Dashboard has a separate privacy policy.

1. Who We Are

We operate the mobile app "Linesol" (the "App"). We are committed to protecting the privacy of participants and collect only the data necessary to provide our services. In this policy, "user data" refers to the personal data collected from participants, as detailed in section 2 below.

2. Personal Data We Collect

Username and password – required for account creation and authentication.
User features – self-inputted demographics in category-feature pairs (e.g., age: 25-34, gender: female). Anonymized versions are saved indefinitely for reports, while profile-tied versions are deleted upon account deletion.
Payout details – for Revolut withdrawals, this may include payout identifiers needed to process payment through Revolut. For USDC withdrawals requested through https://dashboard.linesol.online/usdc, this may include a participant-provided Solana wallet address submitted for the payout, limited payout record data stored in Firebase (such as amount, transaction identifier or on-chain transaction signature, and user ID), and payment-processing data handled by Coinbase or another payout infrastructure provider we use to execute the transfer.
Anonymized survey responses, including relevant self-inputted user features at the time of response – collected only if participants explicitly consent by ticking the AI training consent box.
Firebase installation ID, push token, and last active timestamp – used for delivering notifications (if enabled) and account management.
OneSignal-related notification data (for users who enable push notifications), such as device/app instance identifiers, push subscription status, and message delivery metadata – used only to send and manage push notifications.
Response metadata – including response timestamps, survey identifier, and account activity data used for quality control and authenticity verification purposes.

3. How We Use Participant Data

Username and password: to create and secure participant accounts.
User features: anonymized for generating reports; profile-tied for account management. User features may be aggregated, combined, or transformed into composite variables for analytical purposes, calculated and updated on a 24-hour basis. Participants have visibility over composite features in the app and may opt out by selecting "rather not say" or equivalent opt-out options.
Payout details: to process, execute, and track Revolut and USDC withdrawals, including USDC withdrawals requested through https://dashboard.linesol.online/usdc.
Anonymized survey responses: used for anonymized reports commissioned by companies for AI (LLM) model training and market research (only with explicit consent).
Firebase data (installation ID, push token, last active): for notifications and account management.
OneSignal notification data: to deliver push notifications when enabled, monitor delivery status, and manage notification preferences.
Response metadata and activity patterns: to verify authenticity of accounts and responses, detect fraud, maintain data quality, and ensure compliance with our Terms of Service.
User-feature category/feature nomenclature and related account activity: to enforce platform and legal compliance, which may include modifying or renaming nomenclature, removing/deleting or rejecting non-compliant elements.
Profile update records (including frequency and patterns of changes): to match participants with relevant studies, maintain dataset integrity, and detect/prevent abusive profile manipulation.

3A. Profile Data and Updates

We collect and store records of changes participants make to user features (demographic, behavioral, and preference information participants self-report). This information is used to:

Match participants with relevant studies.
Maintain the statistical integrity of our research datasets.
Detect and prevent abuse, such as excessive or manipulative profile changes.

We track the frequency and patterns of profile updates. If we detect suspicious activity, we may review the account and take appropriate action, including suspension or deletion. This processing is necessary for our legitimate business interests in providing high-quality data to clients and operating a fair platform.

4. Legal Basis under GDPR

Account and core features → performance of contract.
Processing and sharing anonymized response data for client research/AI use → explicit consent (via app checkbox agreeing to this Privacy Policy and the Terms of Service).
Authenticity verification and fraud detection → legitimate interests (maintaining service integrity, preventing fraud, ensuring data quality for clients).
Tracking profile update frequency and patterns for abuse prevention and platform integrity → legitimate interests.
Where data is effectively anonymized and no longer relates to an identifiable person, we may also rely on legitimate interests and the position that such anonymized data may fall outside GDPR personal data scope.

5. Sharing & Third Parties

We do not sell participant data. We share data only with:

Google Firebase (authentication, database).
OneSignal (push notification delivery and related messaging infrastructure, where notifications are enabled).
Revolut (payment processing for Revolut withdrawals).
Coinbase and, where applicable, related blockchain or wallet infrastructure (for USDC payout processing and transaction settlement).
Paying clients (anonymized reports and anonymized raw response datasets for research and analytics, with participant opt-in).
Internal teams and limited third-party service providers, solely as necessary for fraud/abuse prevention and platform integrity safeguards.
Sub-processors listed here: firebase.google.com/terms/subprocessors

5A. Sharing of Anonymized Data

With participant consent, Linesol may share anonymized raw response data with paying clients. This can include one-hot encoded yes/no survey answers and associated user feature vectors, without direct identifiers.

This sharing supports market research, AI training, and custom statistical/modeling work (including multiple correspondence analysis (MCA) for latent dimensions and composite variables), in addition to aggregated reporting.

Shared anonymized datasets do not include direct personal identifiers such as names, email addresses, precise locations, financial account/payment details, or similar direct PII. However, participants acknowledge that a theoretical re-identification risk can still exist in rare cases where unique combinations of features appear.

Client access to anonymized datasets is provided only under contractual restrictions that prohibit: (i) attempts to re-identify participants, (ii) resale or redistribution of the data, and (iii) use beyond the client's internal analysis, research, and modeling purposes.

6. Data Retention

We retain personal data only while participant accounts exist. When participants delete their accounts, all personal data tied to their profiles is permanently deleted within 30 days. Anonymized data (e.g., aggregated reports) may be retained indefinitely as it cannot be linked back to participants.

Participants may also choose to delete their profile-tied user features while keeping their account active. In this case, only the personally identifiable (profile-tied) version of the user features will be deleted. Any anonymized versions already incorporated into reports or aggregated datasets will be retained indefinitely.

If a participant deletes their account while having a non-zero balance, the remaining balance will no longer be withdrawable and will be forfeited. Participants are encouraged to withdraw their earnings before initiating account deletion.

7. Participant Rights (GDPR / CCPA)

Participants have the right to:

Access their personal data.
Correct inaccuracies in their personal data.
Delete their accounts and associated personal data: username and password, user features (in the app and profile-tied), limited data bout which surveys participants answered (without the response field), Firebase ID, push token, and last active timestamp can be deleted by deleting their accounts. Payout details, including limited payout records for Revolut or USDC withdrawals, are retained for accounting, compliance, fraud prevention, and transaction-tracking purposes. Anonymized or aggregated versions of responses already incorporated into reports or shared datasets may be retained indefinitely, as they can no longer be linked back to participants.
Withdraw consent for future AI training by not participating in surveys or deleting their accounts (consent for past survey responses cannot be revoked).
Request data portability for their personal data in a machine-readable format by emailing us.

8. Children

The App is strictly for users aged 18 and above. We do not knowingly collect data from individuals under 18.

9. Changes to this Policy

We may update this Privacy Policy from time to time. If we make material changes, we will notify participants in-app (and may also notify by push notification via OneSignal (if enabled) or email where available) before or when the changes become effective, and we may require re-acceptance before continued use.

10. Contact Us

hello@linesol.online