diff --git a/src/js/contentscript-end.js b/src/js/contentscript-end.js
index a2e786e..466caa2 100644
--- a/src/js/contentscript-end.js
+++ b/src/js/contentscript-end.js
@@ -157,10 +157,6 @@ var collapser = (function() {
         'iframe': 'src',
         'img': 'src'
     };
-    var srcValues = {
-        'iframe': 'about:blank',
-        'img': 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7'
-    };
 
     var PendingRequest = function(target) {
         this.id = requestId++;
@@ -187,7 +183,8 @@ var collapser = (function() {
             return;
         }
         var collapse = response.collapse;
-        var bgImg = response.backgroundImage;
+        var placeholders = response.placeholders;
+        var background = placeholders.background;
         var i = requests.length;
         var request, entry, target, tagName;
         while ( i-- ) {
@@ -206,9 +203,12 @@ var collapser = (function() {
                 target.style.setProperty('display', 'none', 'important');
             } else {
                 tagName = target.localName;
-                target.setAttribute(srcProps[tagName], srcValues[tagName]);
+                target.setAttribute(
+                    srcProps[tagName],
+                    placeholders[tagName].replace('{{url}}', request.url)
+                );
                 target.style.setProperty('border', '1px solid rgba(0,0,0,0.05)', 'important');
-                target.style.setProperty('background', bgImg, 'important');
+                target.style.setProperty('background', background, 'important');
             }
         }
 
@@ -240,13 +240,45 @@ var collapser = (function() {
         }
     };
 
+    var iframeSourceModified = function(mutations) {
+        var i = mutations.length;
+        while ( i-- ) {
+            addFrameNode(mutations[i].target, true);
+        }
+        process();
+    };
+    var iframeSourceObserver = new MutationObserver(iframeSourceModified);
+    var iframeSourceObserverOptions = {
+        attributes: true,
+        attributeFilter: [ 'src' ]
+    };
+
+    var addFrameNode = function(iframe, dontObserve) {
+        // https://github.com/gorhill/uBlock/issues/162
+        // Be prepared to deal with possible change of src attribute.
+        if ( dontObserve !== true ) {
+            iframeSourceObserver.observe(iframe, iframeSourceObserverOptions);
+        }
+        // https://github.com/chrisaljoudi/uBlock/issues/174
+        // Do not remove fragment from src URL
+        var src = iframe.src;
+        if ( src.lastIndexOf('http', 0) !== 0 ) {
+            return;
+        }
+        var req = new PendingRequest(iframe);
+        newRequests.push(new BouncingRequest(req.id, 'iframe', src));
+    };
+
     var addNode = function(target) {
         var tagName = target.localName;
+        if ( tagName === 'iframe' ) {
+            addFrameNode(target);
+            return;
+        }
         var prop = srcProps[tagName];
         if ( prop === undefined ) {
             return;
         }
-
         // https://github.com/chrisaljoudi/uBlock/issues/174
         // Do not remove fragment from src URL
         var src = target[prop];
@@ -462,7 +494,7 @@ var nodeListsAddedHandler = function(nodeLists) {
     };
 
     // This fixes http://acid3.acidtests.org/
-    if ( document.body ) {
+    if ( !document.body ) {
         return;
     }
 
diff --git a/src/js/messaging.js b/src/js/messaging.js
index ffec8ad..79bfffe 100644
--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@@ -510,7 +510,11 @@ var onMessage = function(request, sender, callback) {
             requests: evaluateURLs(tabId, request.requests)
         };
         if ( !response.collapse ) {
-            response.backgroundImage = vAPI.localStorage.getItem('placeholderBackgroundImage');
+            response.placeholders = {
+                background: vAPI.localStorage.getItem('placeholderBackground'),
+                iframe: vAPI.localStorage.getItem('placeholderDocument'),
+                img: vAPI.localStorage.getItem('placeholderImage')
+            };
         }
         break;
 
diff --git a/src/js/start.js b/src/js/start.js
index 84060d9..f5e79b2 100644
--- a/src/js/start.js
+++ b/src/js/start.js
@@ -62,6 +62,37 @@ var jobCallback = function() {
 
 /******************************************************************************/
 
+var defaultLocalUserSettings = {
+    placeholderBackground: [
+            'linear-gradient(0deg,',
+                'rgba(0,0,0,0.02) 25%,',
+                'rgba(0,0,0,0.05) 25%,',
+                'rgba(0,0,0,0.05) 75%,',
+                'rgba(0,0,0,0.02) 75%,',
+                'rgba(0,0,0,0.02)',
+            ') center center / 10px 10px repeat scroll,',
+            'linear-gradient(',
+                '90deg,',
+                'rgba(0,0,0,0.02) 25%,',
+                'rgba(0,0,0,0.05) 25%,',
+                'rgba(0,0,0,0.05) 75%,',
+                'rgba(0,0,0,0.02) 75%,',
+                'rgba(0,0,0,0.02)',
+            ') center center / 10px 10px repeat scroll'
+        ].join(''),
+    placeholderDocument: [
+            'data:text/html,',
+            encodeURIComponent('<html><head><style>'),
+            encodeURIComponent('body {  color: gray; font: 12px sans-serif; margin: 0; padding: 2px; white-space: nowrap; }'),
+            encodeURIComponent('</style></head><body>'),
+            '{{url}}',
+            encodeURIComponent('</body></html>')
+        ].join(''),
+    placeholderImage: 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7'
+};
+
+/******************************************************************************/
+
 var onAllDone = function() {
     µm.webRequest.start();
 
@@ -78,24 +109,13 @@ var onAllDone = function() {
     // for launch time.
     µm.assets.remoteFetchBarrier -= 1;
 
-    if ( vAPI.localStorage.getItem('placeholderBackgroundImage') === null ) {
-        vAPI.localStorage.setItem('placeholderBackgroundImage', [
-            'linear-gradient(0deg,',
-                'rgba(0,0,0,0.02) 25%,',
-                'rgba(0,0,0,0.05) 25%,',
-                'rgba(0,0,0,0.05) 75%,',
-                'rgba(0,0,0,0.02) 75%,',
-                'rgba(0,0,0,0.02)',
-            ') center center / 10px 10px repeat scroll,',
-            'linear-gradient(',
-                '90deg,',
-                'rgba(0,0,0,0.02) 25%,',
-                'rgba(0,0,0,0.05) 25%,',
-                'rgba(0,0,0,0.05) 75%,',
-                'rgba(0,0,0,0.02) 75%,',
-                'rgba(0,0,0,0.02)',
-            ') center center / 10px 10px repeat scroll'
-        ].join(''));
+    for ( var key in defaultLocalUserSettings ) {
+        if ( defaultLocalUserSettings.hasOwnProperty(key) === false ) {
+            continue;
+        }
+        if ( vAPI.localStorage.getItem(key) === null ) {
+            vAPI.localStorage.setItem(key, defaultLocalUserSettings[key]);
+        }
     }
 };