# Users can opt-out of optional telemetry or usage statistics

- **Pattern:** `ab-001310` (`extension-data-privacy.storage-security.telemetry-opt-out`)
- **Severity:** medium
- **Lifecycle:** active
- **Last modified:** 2026-04-18
- **Canonical URL:** https://auditbuffet.com/patterns/ab-001310
- **License:** CC-BY-4.0 — attribute to AuditBuffet Pattern Catalog (https://auditbuffet.com/patterns/ab-001310)

## Why it matters

GDPR Art. 7(3) grants users the right to withdraw consent at any time; CCPA §1798.120 gives users the right to opt out of data collection. An extension that enables telemetry or analytics with no opt-out mechanism denies users these rights by design. The ePrivacy Directive Art. 5(3) specifically covers tracking mechanisms in software — non-essential analytics require prior consent in the EU. Chrome Web Store policy reinforces this: data collected beyond core functionality must be disclosed and controllable. Extensions with hidden or irremovable analytics are a frequent source of negative reviews and one-star ratings that permanently damage store placement.

## Severity rationale

Medium because always-on telemetry without an opt-out violates GDPR Art. 7(3) and CCPA §1798.120 user control rights — the harm scales with user count, and a single store review complaint can trigger a policy audit.

## Remediation

Add a clearly labeled telemetry toggle to your `options.html`, defaulting to disabled:

```html
<label>
  <input type="checkbox" id="optInTelemetry" />
  Share anonymous usage data to help improve this extension
  <a href="/privacy#analytics" target="_blank">(what we collect)</a>
</label>
```

Gate every analytics call behind the stored preference:

```js
chrome.storage.local.get(['optInTelemetry'], ({ optInTelemetry }) => {
  if (optInTelemetry === true) {
    analytics.track('feature_used', eventData);
  }
});
```

Never send analytics on the first run before the user has seen and set the toggle. Cross-reference `analytics-disclosed` to ensure whatever you do send is named in the privacy policy.

## Detection

- **ID:** `telemetry-opt-out`
- **Severity:** `medium`
- **What to look for:** Examine options page for a toggle or setting to disable optional telemetry, analytics, or usage statistics. Check whether the default is opt-in (user must enable) or opt-out (enabled by default with option to disable). Look for clear labeling of what data is collected if telemetry is enabled.
- **Pass criteria:** Count all telemetry or analytics calls in the codebase. A toggle exists in options to enable/disable optional telemetry. Default is opt-in (disabled by default, user can enable if desired). At least 100% of optional telemetry calls must check the user preference before sending. If telemetry is enabled by default, a clear opt-out mechanism is prominent.
- **Fail criteria:** Optional telemetry or analytics are always active with no way to disable. No settings provided. Required telemetry is not clearly separated from optional.
- **Skip (N/A) when:** The extension does not collect any telemetry or analytics data beyond what is strictly necessary for core functionality.
- **Detail on fail:** Describe the telemetry and opt-out issue. Example: `"Google Analytics enabled by default with no option to disable in settings"` or `"Usage statistics collected and sent to external service with no user control or notification."`
- **Remediation:** Add an opt-out toggle to your options page:

  ```html
  <label>
    <input type="checkbox" id="optInTelemetry" />
    Help improve this extension by sharing anonymous usage data
  </label>
  ```

  Then check the flag before sending:

  ```js
  chrome.storage.local.get(['optInTelemetry'], (result) => {
    if (result.optInTelemetry) {
      analytics.track('feature_used');
    }
  });
  ```

## External references

- gdpr Art. 7(3)
- ccpa §1798.120
- eprivacy Art. 5(3)
- external chrome-web-store-user-data-policy — https://developer.chrome.com/docs/webstore/user_data/

Taxons: privacy-consent

HTML version: https://auditbuffet.com/patterns/ab-001310