this fixes https://github.com/gorhill/uBlock/issues/135 and #1329

src/js/background.js

@@ -71,9 +71,11 @@ return {
     netWhitelist: {},
     netWhitelistModifyTime: 0,
     netWhitelistDefault: [
+        'about-scheme',
         'behind-the-scene',
         'chrome-extension-scheme',
         'chrome-scheme',
+        'loopconversation.about-scheme',
         'opera-scheme'
     ].join('\n').trim(),
 

src/js/start.js

@@ -81,6 +81,16 @@ var onVersionReady = function(lastVersion) {
         );
         µb.saveWhitelist();
     }
+    // https://github.com/gorhill/uBlock/issues/135#issuecomment-96677379
+    // `about:loopconversation` is used by Firefox for its Hello service
+    if ( lastVersion.localeCompare('0.9.3.5') <= 0 ) {
+        µb.netWhitelist = µb.whitelistFromString(
+            µb.stringFromWhitelist(µb.netWhitelist) +
+            '\n' +
+            'loopconversation.about-scheme'
+        );
+        µb.saveWhitelist();
+    }
     if ( lastVersion !== vAPI.app.version ) {
         vAPI.storage.set({ version: vAPI.app.version });
     }

src/js/tab.js

@@ -55,13 +55,15 @@ var µb = µBlock;
         return uri.normalizedURI();
     }
 
-    var url = 'http://' + scheme + '-scheme/';
+    var fakeHostname = scheme + '-scheme';
 
     if ( uri.hostname !== '' ) {
-        url += uri.hostname + '/';
+        fakeHostname = uri.hostname + '.' + fakeHostname;
+    } else if ( scheme === 'about' && uri.path !== '' ) {
+        fakeHostname = uri.path + '.' + fakeHostname;
     }
 
-    return url;
+    return 'http://' + fakeHostname + '/';
 };
 
 /******************************************************************************/