--- a/browser/locales/en-US/chrome/browser/browser.properties
+++ b/browser/locales/en-US/chrome/browser/browser.properties
@@ -381,17 +381,17 @@ keywordPrompt.noButton.accessKey  = N
 webapps.install = Install
 webapps.install.accesskey = I
 #LOCALIZATION NOTE (webapps.requestInstall) %1$S is the web app name, %2$S is the site from which the web app is installed
 webapps.requestInstall = Do you want to install "%1$S" from this site (%2$S)?
 webapps.install.success = Application Installed
 
 # Telemetry opt-out prompt for Aurora and Nightly
 # LOCALIZATION NOTE (telemetryOptOutPrompt): %1$S and %3$S will be replaced by
-# brandFullName, and %2$S by the value of the toolkit.telemetry.server_owner preference.
+# brandShortName, and %2$S by the value of the toolkit.telemetry.server_owner preference.
 telemetryOptOutPrompt = %1$S sends information about performance, hardware, usage and customizations back to %2$S to help improve %3$S.
 
 # LOCALIZATION NOTE (fullscreen.entered): displayed when we enter HTML5 fullscreen mode, %S is the domain name of the focused website (e.g. mozilla.com).
 fullscreen.entered=%S is now fullscreen.
 # LOCALIZATION NOTE (fullscreen.rememberDecision): displayed when we enter HTML5 fullscreen mode, %S is the domain name of the focused website (e.g. mozilla.com).
 fullscreen.rememberDecision=Remember decision for %S
 
 # LOCALIZATION NOTE (social.activated.description): %1$S is the name of the social provider, %2$S is brandShortName (e.g. Firefox)

--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -7101,27 +7101,29 @@ var RemoteDebugger = {
 
   _stop: function rd_start() {
     DebuggerServer.closeListener();
     dump("Remote debugger stopped");
   }
 };
 
 var Telemetry = {
-  _PREF_TELEMETRY_PROMPTED: "toolkit.telemetry.prompted",
 #ifdef MOZ_TELEMETRY_ON_BY_DEFAULT
   _PREF_TELEMETRY_ENABLED: "toolkit.telemetry.enabledPreRelease",
+  _PREF_TELEMETRY_DISPLAYED: "toolkit.telemetry.notifiedOptOut",
 #else
   _PREF_TELEMETRY_ENABLED: "toolkit.telemetry.enabled",
+  _PREF_TELEMETRY_DISPLAYED: "toolkit.telemetry.prompted",
 #endif
   _PREF_TELEMETRY_REJECTED: "toolkit.telemetry.rejected",
   _PREF_TELEMETRY_SERVER_OWNER: "toolkit.telemetry.server_owner",
 
-  // This is used to reprompt users when privacy message changes
-  _TELEMETRY_PROMPT_REV: "@MOZ_TELEMETRY_DISPLAY_REV@",
+  // This is used to reprompt Beta/GA users and notify again
+  // Nightly/Aurora users when privacy message changes
+  _TELEMETRY_DISPLAY_REV: @MOZ_TELEMETRY_DISPLAY_REV@,
 
   init: function init() {
     Services.obs.addObserver(this, "Preferences:Set", false);
     Services.obs.addObserver(this, "Telemetry:Add", false);
     Services.obs.addObserver(this, "Telemetry:Prompt", false);
   },
 
   uninit: function uninit() {
@@ -7136,72 +7138,135 @@ var Telemetry = {
     histogram.add(aValue);
   },
 
   observe: function observe(aSubject, aTopic, aData) {
     if (aTopic == "Preferences:Set") {
       // if user changes telemetry pref, treat it like they have been prompted
       let pref = JSON.parse(aData);
       if (pref.name == this._PREF_TELEMETRY_ENABLED)
-        Services.prefs.setIntPref(this._PREF_TELEMETRY_PROMPTED, this._TELEMETRY_PROMPT_REV);
+        Services.prefs.setIntPref(this._PREF_TELEMETRY_DISPLAYED, this._TELEMETRY_DISPLAY_REV);
     } else if (aTopic == "Telemetry:Add") {
       let json = JSON.parse(aData);
       this.addData(json.name, json.value);
     } else if (aTopic == "Telemetry:Prompt") {
 #ifdef MOZ_TELEMETRY_REPORTING
       this.prompt();
 #endif
     }
   },
 
   prompt: function prompt() {
+    let brandShortName = Strings.brand.GetStringFromName("brandShortName");
     let serverOwner = Services.prefs.getCharPref(this._PREF_TELEMETRY_SERVER_OWNER);
-    let telemetryPrompted = null;
+    let telemetryEnabled = Services.prefs.getBoolPref(this._PREF_TELEMETRY_ENABLED);
+    let message;
+    let buttons;
     let self = this;
+
+    /*
+     * Display an opt-out notification when telemetry is enabled by default,
+     * an opt-in prompt otherwise.
+     *
+     * But do not display this prompt/notification if:
+     *
+     * - The last accepted/refused policy (either by accepting the prompt or by
+     *   manually flipping the telemetry preference) is already at version
+     *   TELEMETRY_DISPLAY_REV.
+     */
+    let telemetryDisplayed;
     try {
-      telemetryPrompted = Services.prefs.getIntPref(this._PREF_TELEMETRY_PROMPTED);
-    } catch (e) { /* Optional */ }
-
-    // If the user has seen the latest telemetry prompt, do not prompt again
-    // else clear old prefs and reprompt
-    if (telemetryPrompted === this._TELEMETRY_PROMPT_REV)
+      telemetryDisplayed = Services.prefs.getIntPref(self._PREF_TELEMETRY_DISPLAYED);
+    } catch(e) {}
+    if (telemetryDisplayed === self._TELEMETRY_DISPLAY_REV)
+      return;
+
+#ifdef MOZ_TELEMETRY_ON_BY_DEFAULT
+    /*
+     * Additionally, in opt-out builds, don't display the notification if:
+     *
+     * - Telemetry is disabled
+     * - Telemetry was explicitly refused through the UI
+     * - Opt-in telemetry was already enabled, don't notify the user until next
+     *   policy update. (Do the check only at first run with opt-out builds)
+     */
+
+    let telemetryEnabled = Services.prefs.getBoolPref(self._PREF_TELEMETRY_ENABLED);
+    if (!telemetryEnabled)
+      return;
+
+    // If telemetry was explicitly refused through the UI,
+    // also disable opt-out telemetry and bail out.
+    let telemetryRejected = false;
+    try {
+      telemetryRejected = Services.prefs.getBoolPref(self._PREF_TELEMETRY_REJECTED);
+    } catch(e) {}
+    if (telemetryRejected) {
+      Services.prefs.setBoolPref(self._PREF_TELEMETRY_ENABLED, false);
+      Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
       return;
-
-    Services.prefs.clearUserPref(this._PREF_TELEMETRY_PROMPTED);
-    Services.prefs.clearUserPref(this._PREF_TELEMETRY_ENABLED);
-
-    let buttons = [
+    }
+
+    // If opt-in telemetry was already enabled, don't notify the user until next
+    // policy update. (Do the check only at first run with opt-out builds)
+    let optInTelemetryEnabled = false;
+    try {
+      optInTelemetryEnabled = Services.prefs.getBoolPref("toolkit.telemetry.enabled");
+    } catch(e) {}
+    if (optInTelemetryEnabled && telemetryDisplayed === undefined) {
+      Services.prefs.setBoolPref(self._PREF_TELEMETRY_REJECTED, false);
+      Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
+      return;
+    }
+
+    message = Strings.browser.formatStringFromName("telemetry.optout.message",
+                                                    [brandShortName, serverOwner, brandShortName], 3);
+    buttons = [
+      {
+        label: Strings.browser.GetStringFromName("telemetry.optout.ok"),
+        callback: function () {
+          Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
+        }
+      }
+    ];
+#else
+    // Clear old prefs and reprompt
+    Services.prefs.clearUserPref(self._PREF_TELEMETRY_DISPLAYED);
+    Services.prefs.clearUserPref(self._PREF_TELEMETRY_ENABLED);
+    Services.prefs.clearUserPref(self._PREF_TELEMETRY_REJECTED);
+
+    message = Strings.browser.formatStringFromName("telemetry.optin.message2",
+                                                  [serverOwner, brandShortName], 2);
+    buttons = [
       {
         label: Strings.browser.GetStringFromName("telemetry.optin.yes"),
         callback: function () {
-          Services.prefs.setIntPref(self._PREF_TELEMETRY_PROMPTED, self._TELEMETRY_PROMPT_REV);
+          Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
           Services.prefs.setBoolPref(self._PREF_TELEMETRY_ENABLED, true);
         }
       },
       {
         label: Strings.browser.GetStringFromName("telemetry.optin.no"),
         callback: function () {
-          Services.prefs.setIntPref(self._PREF_TELEMETRY_PROMPTED, self._TELEMETRY_PROMPT_REV);
+          Services.prefs.setIntPref(self._PREF_TELEMETRY_DISPLAYED, self._TELEMETRY_DISPLAY_REV);
           Services.prefs.setBoolPref(self._PREF_TELEMETRY_REJECTED, true);
         }
       }
     ];
-
-    let brandShortName = Strings.brand.GetStringFromName("brandShortName");
-    let message = Strings.browser.formatStringFromName("telemetry.optin.message2", [serverOwner, brandShortName], 2);
+#endif
     let learnMoreLabel = Strings.browser.GetStringFromName("telemetry.optin.learnMore");
     let learnMoreUrl = Services.urlFormatter.formatURLPref("app.support.baseURL");
     learnMoreUrl += "how-can-i-help-submitting-performance-data";
     let options = {
       link: {
         label: learnMoreLabel,
         url: learnMoreUrl
       }
     };
-    NativeWindow.doorhanger.show(message, "telemetry-optin", buttons, BrowserApp.selectedTab.id, options);
+    NativeWindow.doorhanger.show(message, "telemetry-prompt", buttons, BrowserApp.selectedTab.id, options);
   },
 };
 
 let Reader = {
   // Version of the cache database schema
   DB_VERSION: 1,
 
   DEBUG: 0,

--- a/mobile/android/locales/en-US/chrome/browser.properties
+++ b/mobile/android/locales/en-US/chrome/browser.properties
@@ -62,16 +62,20 @@ safeBrowsingDoorhanger=This site has bee
 blockPopups.label=Block Popups
 
 # Telemetry
 # %1$S = server owner (Mozilla); %2$S = product name (Firefox)
 telemetry.optin.message2=Send info to %1$S so that we can improve %2$S?
 telemetry.optin.learnMore=Learn more
 telemetry.optin.yes=Yes
 telemetry.optin.no=No
+# LOCALIZATION NOTE (telemetry.optout.message): %1$S and %3$S will be replaced by
+# brandShortName, and %2$S by the value of the toolkit.telemetry.server_owner preference.
+telemetry.optout.message=%1$S sends information about performance, hardware, usage and customizations back to %2$S to help improve %3$S.
+telemetry.optout.ok=OK
 
 # XPInstall
 xpinstallPromptWarning2=%S prevented this site (%S) from asking you to install software on your device.
 xpinstallPromptAllowButton=Allow
 xpinstallDisabledMessageLocked=Software installation has been disabled by your system administrator.
 xpinstallDisabledMessage2=Software installation is currently disabled. Press Enable and try again.
 xpinstallDisabledButton=Enable